# Opposing Counsel's Fake AI Citations: How to Respond

> The other side's brief cites cases that do not exist. What to verify first, how Rule 11's safe harbor works, and why both California opinions paid the court.

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# Opposing Counsel Filed Fabricated AI Citations: How to Respond Without Losing Your Motion
You are reading the other side's brief and a citation will not resolve. Then a second one will not. The instinct is to move for sanctions immediately, and that instinct is what cost the opposing party in the two published California opinions on AI-fabricated citations. In both, the court sanctioned the offending lawyer and awarded the other side nothing. Understanding why is the difference between a motion that works and one that hands your opponent a win on the record.

By [Jamie Kloncz](https://rankshieldlegal.com/about/), Founder, RankShield ** 24 min read ** Published August 22, 2026

Almost everything written about AI-fabricated citations addresses the lawyer who filed them. This is the other chair. When opposing counsel files a brief resting on authorities that do not exist, you have a tactical opportunity and a procedural minefield, and the two published California appellate opinions on the subject show exactly how a party can be completely right about the fabrication and still recover nothing.
In Noland v. Land of the Free, L.P. (2025), the court sanctioned appellant's counsel $10,000 for briefs replete with fabricated quotations and citations. The money was payable to the court. Respondent was expressly awarded nothing, and the reason is instructive: respondent's counsel did not alert the court to the fabricated citations and appeared unaware of them until the court issued an order to show cause [[2]](#ref-2) [[6]](#ref-6).
In Del Biaggio v. Bansen (2026), the opposing party did catch the fabrications and moved for sanctions. They still recovered nothing. The court wrote plainly: "While we order Floyd to pay sanctions to the court, we decline to award sanctions to the Bansens" [[1]](#ref-1). Their motion had characterized the entire appeal as frivolous when the underlying argument was meritorious, and the overreach cost them the award.
So there are two reliable ways to end up with nothing: fail to catch the fabrication, or catch it and ask for too much. This article covers how to verify before you accuse, how the Rule 11 safe harbor actually sequences, what to request and what to leave out, and how to build the record while you check. It is written from the perspective of a verification vendor, not a law firm, and it is informational rather than legal advice; procedure varies by court and jurisdiction, so confirm the rules that govern your matter with counsel.

## Verify before you accuse, because the accusation is itself a filing
A citation you cannot find is not yet a fabricated citation. Before alleging fabrication, distinguish among four possibilities: the authority does not exist, it exists but is cited incorrectly, it exists and is quoted inaccurately, or your search was incomplete. An accusation of fabrication is a serious charge, and the motion carrying it is itself subject to Rule 11 [[3]](#ref-3).
The failure mode here is asymmetric. If you are right and slow, you lose a little time. If you are wrong and fast, you have filed a paper accusing another lawyer of fabricating authority, and that paper carries your signature and its own certification obligations.
Four different problems produce the same initial symptom of a citation that will not resolve. The authority may genuinely not exist, which is fabrication. It may exist under a different reporter, volume, or docket number, which is a citation error. It may exist and be real while the quotation attributed to it is invented or the holding is mischaracterized, which is the more common and more consequential defect. Or your search may simply have missed it, which happens with unpublished dispositions, recent decisions not yet indexed, and authorities from databases you do not subscribe to.
Those distinctions matter because they call for different responses. A miscited but real case is usually a correction, not a sanctions matter. A real case with an invented quotation is closer to the conduct courts have actually punished, and it is precisely the defect that separates a fabricated authority from a misgrounded one, a distinction covered in our guide on [fabricated versus misgrounded citations](https://rankshieldlegal.com/blog/fabricated-vs-misgrounded-legal-ai-citations).
Run the same three checks you would run on your own brief. Confirm the authority exists and is identified correctly. Confirm the quotation and characterization match the source. Confirm it remains good law. Do that for every questionable citation before you draft anything, and search more than one database before concluding an authority does not exist.
Independent testing gives a sense of the base rate you are working against: a Stanford study of leading legal AI research tools found inaccurate answers on a meaningful share of queries, with figures reported around 17 percent for one product and 33 percent for another in 2024 testing [[4]](#ref-4). That is why the pattern is worth checking for, and also why a single unresolvable citation is not by itself proof of anything.

## Rule 11's safe harbor is a rigid sequence, and skipping it is itself a violation
In federal court, Rule 11(c)(2) requires that a sanctions motion be made separately from any other motion, describe the specific offending conduct, and be served on the opponent. It must not be filed if the challenged paper is withdrawn or appropriately corrected within 21 days after service. Serve first, wait, then file only if the problem stands [[3]](#ref-3).
The rule's text is specific and the sequence is not optional. Rule 11(c)(2) provides that a motion for sanctions "must be made separately from any other motion and must describe the specific conduct that allegedly violates Rule 11(b)," and that it "must be served under Rule 5, but it must not be filed or be presented to the court if the challenged paper, claim, defense, contention, or denial is withdrawn or appropriately corrected within 21 days after service or within another time the court sets" [[3]](#ref-3).
Three requirements are doing work in that sentence. The motion must stand alone, so folding a sanctions request into your opposition brief does not comply. It must identify the specific conduct, so a general complaint about the quality of the other side's briefing does not comply. And it must be served on the opponent before it is filed, with a 21-day window in which they can withdraw or correct the paper.
That window is the safe harbor, and its purpose is to give the offending party a chance to fix the problem rather than to guarantee you a sanction. If opposing counsel withdraws the fabricated citations within 21 days, the motion should not be filed. That is the rule operating as designed, not a loss.
It is worth appreciating what the safe harbor offers the other side, because it explains why many opponents take it. In the federal system the consequences of letting fabricated authority stand have become substantial: in LNU v. Blanche, a published and precedential Ninth Circuit decision, two attorneys were sanctioned $2,500 each, suspended from practice before the court for six months, and required to disclose generative AI use in future filings, with the panel focusing on the combination of nonexistent cases, misattributed quotations, and the subsequent lack of candor [[5]](#ref-5). A lawyer served with a well-documented motion is weighing that against a withdrawal, and withdrawal is usually the rational choice.
A letter is not a motion. Sending a sharply worded email pointing out the fabrications, waiting 21 days, and then filing does not satisfy the rule, because what must be served is the motion itself. This is a recurring trap, and the correction is simple: draft the actual motion, serve that, then diary the date.
Timing runs in both directions. Committee commentary indicates the motion should be served promptly after the offending paper is filed, so sitting on a known fabrication for months can create its own timeliness problem. Move deliberately, not slowly.
None of this describes state practice, which varies considerably. Del Biaggio and Noland were California appellate matters decided under California rules, and a state court may have a different mechanism, a different notice period, or none at all. Confirm the specific procedure that governs your matter.

- **Verify every questionable citation yourself** Confirm existence, quotation accuracy, and good-law status across more than one database before concluding anything is fabricated. Record what you checked and when as you go.
- **Classify the defect precisely** Separate genuine fabrications from miscitations and from real cases with invented quotations. The response and the remedy differ, and precision here is what keeps the motion narrow.
- **Draft the motion as a standalone document** Rule 11(c)(2) requires the motion be made separately from any other motion and describe the specific conduct. Do not fold it into your opposition.
- **Serve it and start the 21-day clock** Serve under Rule 5 and diary the date. Do not file. If the challenged paper is withdrawn or appropriately corrected within the window, the motion should not be presented to the court.
- **File only if the defect stands, and ask narrowly** If the 21 days pass without correction, file. Request what is proportionate to the specific conduct you identified rather than a characterization of the whole case.

Source: FRCP 11; Del Biaggio v. Bansen (2026); Noland v. Land of the Free (2025) Download SVG

## The overreach trap: how Del Biaggio's opponent won the point and lost the award
The Bansens correctly identified fabricated quotations in their opponent's opening brief and moved for sanctions. The court sanctioned counsel $1,500 payable to the court and declined to award them anything, because their motion characterized the entire appeal as frivolous when the underlying argument was in fact meritorious [[1]](#ref-1).
This is the most useful cautionary tale available, because the party that lost the award did the hard part correctly. They read the brief, found the fictional quotations, and brought them to the court's attention. Then they framed the motion around a claim the record would not support.
The court's disposition is worth reading closely. It rejected the argument that the appeal was frivolous, vacated a separate trial-court sanction, and ordered counsel to pay $1,500 to the court for the misstatements and the failure to correct them promptly. On the opposing party's request it was explicit: "While we order Floyd to pay sanctions to the court, we decline to award sanctions to the Bansens" [[1]](#ref-1).
The mechanism of the loss is proportionality. Fabricated citations in a brief are serious and specific. "This entire appeal is frivolous" is a much larger claim requiring the whole appeal to lack merit, and here the underlying argument was meritorious, so the larger claim failed and took the award with it. Having tied the request to the larger claim, the movant had nothing left when it did not land.
Rule 11 embeds the same proportionality principle in federal practice. A sanction "must be limited to what suffices to deter repetition of the conduct or comparable conduct by others similarly situated" [[3]](#ref-3). A request calibrated to that standard is easier for a court to grant than one that asks it to condemn the entire case.
The practical lesson is to separate the defect from the case. Ask the court to address the fabricated authorities specifically. Resist the temptation to argue that the fabrications prove the opposing position is meritless, because those are different propositions and bundling them puts the smaller, well-supported one at risk of the larger one's failure.
Del Biaggio and Noland are California appellate decisions applying California rules. The proportionality principle they illustrate has a federal analogue in Rule 11(c)(4), but the procedures, notice requirements, and available remedies differ by jurisdiction. Confirm the rules governing your matter with counsel before relying on any of this.

## The other way to get nothing: not catching it at all
In Noland, the court imposed $10,000 on appellant's counsel for briefs replete with fabricated quotations, payable to the court. Respondent received nothing, and the stated reason was that respondent's counsel did not alert the court to the fabrications and appeared unaware of them until the court issued its own order to show cause [[2]](#ref-2) [[6]](#ref-6).
If Del Biaggio shows the cost of overreaching, Noland shows the cost of not reading carefully. Twenty-one of the twenty-three case quotations in the opening brief were fabrications, and the party opposing that brief did not raise it. The court found the problem itself and issued an order to show cause [[2]](#ref-2) [[6]](#ref-6).
Consider what that means practically. Opposing counsel read a brief in which the overwhelming majority of quoted authority was invented, responded to it, and did not notice. The fabrications were not subtle in volume; they were simply not checked.
The cost was concrete. Respondent absorbed the expense of briefing against fabricated authority and received no compensation for it, because the court declined to award fees, costs, or sanctions payable to respondent [[6]](#ref-6). The party that did the work of opposing an unfounded brief got nothing, and the sanction went to the court.
This reframes cite-checking the other side's brief from optional diligence into economically rational practice. Verifying the authorities in an opponent's brief is work you are likely doing partially anyway when you assess their argument. Doing it systematically converts a defensive task into a potential remedy and, at minimum, prevents you from arguing against authority that does not exist.
It also has a client-facing dimension. A client who later learns that the other side's brief was substantially fabricated, and that their own counsel did not notice, will have a reasonable question about the review the brief received. Our guide on [verifying AI case citations](https://rankshieldlegal.com/blog/verify-ai-case-citations-before-filing) covers the mechanics; the point here is that the same checks apply to briefs you did not write.

## What to ask for, and what to leave out
Ask for what is proportionate to the specific conduct: correction of the record, fees attributable to responding to the fabricated material, and where warranted a deterrent sanction. Leave out characterizations of the whole case, requests for terminating sanctions on a citation defect, and any figure you cannot tie to work actually performed.
The request is where a well-investigated motion most often fails, because the drafting lawyer is by then genuinely angry and the anger shows in the relief sought.
Three requests tend to be well-matched to the conduct. Correction of the record, meaning an order striking or requiring withdrawal of the offending material, addresses the immediate problem and is difficult to oppose. Fees attributable to the specific work the fabrication caused, documented by time records tied to the defect, is a concrete number a court can evaluate. And a deterrent sanction where the conduct warrants it, framed in the language courts use, fits the standard Rule 11(c)(4) actually applies.
Three requests tend to hurt. Characterizing the entire case or appeal as frivolous is the Del Biaggio error, and it puts your well-supported request at risk of your unsupported one. Asking for terminating sanctions over a citation defect will read as disproportionate absent something considerably more serious. And an unsupported dollar figure invites the court to substitute its own, usually lower, number, or to deny the request as unsubstantiated.
Note also that the sanction may not be payable to you even when the court agrees the conduct was sanctionable. In both published California opinions the money went to the court. Federal practice permits an award of attorney's fees to the movant where warranted, but Rule 11's stated purpose is deterrence rather than compensation, and a motion pitched primarily as a fee application may sit awkwardly against that standard [[3]](#ref-3).
A useful drafting discipline is to write the request first, in one sentence, before drafting the argument. If that sentence cannot be justified by the specific conduct you documented, the problem is the request rather than the argument, and it is much cheaper to discover that before the motion is served.
Ask for Why it lands Avoid Why it fails
Correction or striking of the offending material Addresses the specific defect; hard to oppose A finding that the whole case is frivolous The Del Biaggio error; unsupported by the record and takes the rest with it [1]
Fees tied to the work the fabrication caused A concrete number backed by time records An unsupported lump sum Invites a lower substituted figure or outright denial
A deterrent sanction where warranted Matches the Rule 11(c)(4) standard [3] Terminating sanctions over a citation defect Disproportionate absent much more serious conduct
Relief framed to the specific conduct Courts grant narrow, well-evidenced requests Relief framed to your opponent's character Reads as advocacy rather than a procedural remedy

## Build the record while you check, not afterward
Your verification work is evidence, and it is worth far more if it exists contemporaneously. Log each citation checked, the databases searched, the result, and the date, as you do it. A motion supported by a dated verification record is materially stronger than one supported by an assertion that you looked.
A sanctions motion asserting that certain authorities do not exist is a factual claim you may be asked to support. The support is your search record, and reconstructing it later is both harder and less persuasive than capturing it as you work.
Record four things per questionable citation: the citation exactly as it appears in the opponent's brief, which databases you searched, what each returned, and the date and time of the search. That last element matters more than it appears, because it establishes that your search preceded your accusation rather than following it.
Searching more than one source is worth doing for its own sake and worth documenting for the motion. "Not found in two independent databases" is a materially stronger statement than "not found," and it forecloses the obvious response that you simply looked in the wrong place.
The fee request depends on the same discipline. If you intend to seek fees attributable to the fabricated material, the time has to be recorded against that work specifically while you are doing it. Time reconstructed at the end of a matter and attributed to a defect after the fact is exactly the kind of figure a court discounts.
This is the same record a firm should be generating for its own filings, applied to a brief it did not write. RankShield Legal certifies which cited authorities exist, are quoted accurately, and remain good law, and records who ran the check and when, so the verification is provable rather than merely asserted. That is useful on your own brief and equally useful on your opponent's, since the underlying question is identical.
4 fields log per questionable citation: the citation as written, databases searched, what each returned, and the date and time of the search

## What to do when it is your own client who wants blood
A client who learns the other side fabricated authority often wants the most aggressive possible response, and that pressure is where proportionality gets abandoned. The counseling task is to explain that the narrow motion is more likely to succeed than the aggressive one, and that both published California opinions paid the court rather than the opposing party.
The pressure is understandable. From a client's perspective, opposing counsel has been caught doing something that looks like cheating, and a measured response can read as insufficient advocacy.
Three things are worth explaining. First, that the narrow motion is the one more likely to be granted, and that Del Biaggio is a documented example of a party losing an award by asking for too much [[1]](#ref-1). Second, that a sanction is often payable to the court rather than to the client, so the realistic financial upside may be limited to fees attributable to the specific work caused. Third, that the conduct is now on the record regardless, which has value in how the court reads that lawyer's remaining filings.
It also helps to be clear about what the motion is for. A Rule 11 sanction is aimed at deterrence rather than compensation [[3]](#ref-3). A client expecting a windfall from a citation defect is working from a premise the rule does not support, and that expectation is better corrected before the motion than after the ruling.
There is a strategic argument for restraint that clients tend to find persuasive. A narrow, well-evidenced motion that succeeds is worth more than an aggressive one that fails, because a denied sanctions motion is itself part of the record and can color how the court views subsequent applications from you.
Finally, keep the case and the conduct separate in the client's mind as well as in the motion. Fabricated citations in a brief say something serious about how that brief was prepared. They do not establish that the opposing party's underlying position lacks merit, and a litigation strategy built on the assumption that it does is building on the same overreach that cost the Bansens their award [[1]](#ref-1).

## A standing practice: cite-check the briefs you did not write
The durable takeaway is procedural rather than tactical. Add opponent-brief verification to your standard response workflow so it happens by default. Noland is the case for it: respondent absorbed the cost of opposing a brief where twenty-one of twenty-three quotations were fabricated, did not catch it, and recovered nothing [[2]](#ref-2) [[6]](#ref-6).
Most firms have a workflow for verifying their own citations and none for verifying the other side's. That asymmetry made sense when fabricated authority was rare. It makes less sense now.
The practice itself is small. When a response brief is assigned, the authorities in the brief being answered get the same three checks the firm applies to its own filings: existence, quotation accuracy, and good-law status. In most matters this confirms everything is fine and costs an hour. In the matters where it does not, it is the difference between Noland's respondent and a party with a documented, timely, narrow motion.
Scope it sensibly rather than exhaustively. Authorities the opponent relies on most heavily, quotations doing real analytical work, and anything you cannot immediately place are worth the check. A string cite of well-known cases for an uncontroversial proposition is not where fabrications tend to matter.
Assign it explicitly, because work that belongs to everyone belongs to no one. A paralegal can perform and record the checks and that work is valuable and billable; the lawyer signing any resulting motion needs to have confirmed the findings personally, for the same reason the duty is non-delegable on your own filings, as [Del Biaggio held in the context of a lawyer's own brief](https://rankshieldlegal.com/blog/lawyer-cite-check-ai-not-paralegal-del-biaggio).
The economics favor the practice even when nothing is found. You are reading those authorities anyway to answer them. Verifying them as you read converts reading you were already doing into a record you might need, and ensures you never build an argument against a case that does not exist.

Test yourself
## Test yourself on responding to fabricated citations
Five questions on the two ways to be completely right and recover nothing.

- 1 Why did the opposing party in Del Biaggio recover nothing despite catching the fabrications? They missed the safe harbor deadline Their motion characterized the entire appeal as frivolous when the underlying argument was meritorious They failed to serve the motion **Answer:** Their motion characterized the entire appeal as frivolous when the underlying argument was meritorious The court wrote: "While we order Floyd to pay sanctions to the court, we decline to award sanctions to the Bansens." Fabricated citations are a specific defect; "the whole appeal is frivolous" is a much larger claim, and tying the request to it meant nothing was left when it failed.
- 2 Under Rule 11(c)(2), what must happen before a sanctions motion is filed? It must be served, with 21 days to withdraw or correct It must be attached to the opposition brief The court must grant leave **Answer:** It must be served, with 21 days to withdraw or correct The motion must be made separately, describe the specific conduct, and be served under Rule 5. It must not be filed if the challenged paper is withdrawn or appropriately corrected within 21 days after service. Serve first, wait, then file only if the problem stands.
- 3 Does a strongly worded letter start the safe harbor clock? Yes, if it identifies the citations No, what must be served is the motion itself Only in appellate practice **Answer:** No, what must be served is the motion itself This is a recurring trap. Sending an email and waiting 21 days does not comply, because Rule 11(c)(2) requires service of the motion. Draft the actual motion, serve that, and diary the date.
- 4 In Noland, why did respondent receive nothing? The sanction was reversed on appeal Respondent's counsel did not catch the fabrications; the court found them itself Respondent settled before the ruling **Answer:** Respondent's counsel did not catch the fabrications; the court found them itself Twenty-one of twenty-three quotations in the opening brief were fabricated, and respondent appeared unaware until the court issued an order to show cause. The $10,000 went to the court, and fees, costs and sanctions payable to respondent were declined.
- 5 What is the standard a Rule 11 sanction is measured against? Full compensation for the movant's costs What suffices to deter repetition of the conduct A statutory minimum per fabricated citation **Answer:** What suffices to deter repetition of the conduct Rule 11(c)(4) limits a sanction to what suffices to deter repetition of the conduct or comparable conduct by others similarly situated. That is a deterrence standard, not a compensatory one, which is why a motion pitched mainly as a fee application can sit awkwardly.
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- **What should I do first if I think opposing counsel used AI to fabricate citations?** Verify before you accuse, because the accusation is itself a filing subject to its own certification obligations. A citation you cannot find is not yet a fabricated citation. Four different problems produce the same symptom: the authority genuinely does not exist, it exists but is cited incorrectly, it exists and is real while the quotation attributed to it is invented, or your search was incomplete. Run the same three checks you would run on your own brief, confirming that each authority exists and is identified correctly, that the quotation and characterization match the source, and that it remains good law. Search more than one database before concluding something does not exist, since unpublished dispositions and very recent decisions are common sources of false negatives. Document what you checked and when as you go, because that record is the evidence supporting any motion you later bring.
- **How does the Rule 11 safe harbor work?** In federal court, Rule 11(c)(2) requires that a motion for sanctions be made separately from any other motion and describe the specific conduct alleged to violate Rule 11(b). The motion must be served under Rule 5, and it must not be filed or presented to the court if the challenged paper, claim, defense, contention, or denial is withdrawn or appropriately corrected within 21 days after service, or within another time the court sets. The sequence is rigid: serve the motion first, wait the full window, then file only if the problem stands. A letter does not satisfy the requirement, because what must be served is the motion itself, so a sharply worded email followed 21 days later by a filing does not comply. Committee commentary also indicates the motion should be served promptly after the offending paper is filed, so a long delay can create a timeliness problem. State procedure varies considerably and may differ entirely.
- **Why did the opposing party in Del Biaggio get nothing?** Because their motion asked for too much. The Bansens correctly identified fabricated quotations in the appellant's opening brief and moved for sanctions, but they characterized the entire appeal as frivolous. The court found the underlying argument meritorious, rejected the frivolousness claim, and was explicit about the result: "While we order Floyd to pay sanctions to the court, we decline to award sanctions to the Bansens." Counsel was ordered to pay $1,500 to the court for the misstatements and the failure to correct them promptly. The mechanism of the loss is proportionality. Fabricated citations are a serious and specific defect; "this entire appeal is frivolous" is a much larger claim requiring the whole appeal to lack merit. Having tied their request to the larger claim, the movant had nothing left when it failed. Separate the defect from the case when framing the request.
- **Will I get paid if the court sanctions opposing counsel?** Not necessarily, and in both published California opinions the answer was no. In Del Biaggio the $1,500 was payable to the court and the opposing party was awarded nothing. In Noland the $10,000 was likewise payable to the court, and the court declined to award attorneys' fees, costs, or sanctions payable to respondent. Federal practice under Rule 11 does permit an award of attorney's fees to the movant where warranted, but the rule's stated standard is that a sanction must be limited to what suffices to deter repetition of the conduct, which is a deterrence purpose rather than a compensatory one. A motion pitched primarily as a fee application can sit awkwardly against that standard. If you do intend to seek fees attributable to the fabricated material, record that time against the specific work while you are doing it rather than reconstructing it later.
- **Should I cite-check the other side's brief as a matter of routine?** There is a strong case for it, and Noland is that case. Twenty-one of the twenty-three case quotations in the opening brief were fabrications, and respondent's counsel did not alert the court, appearing unaware of the problem until the court issued its own order to show cause. Respondent absorbed the cost of briefing against fabricated authority and recovered nothing. The practice itself is small: when a response brief is assigned, apply the same three checks to the authorities in the brief being answered that you apply to your own filings. Scope it sensibly rather than exhaustively, concentrating on authorities the opponent relies on heavily, quotations doing real analytical work, and anything you cannot immediately place. The economics favour it even when nothing is found, because you are reading those authorities anyway to answer them, and verifying as you read ensures you never build an argument against a case that does not exist.
- **What should a sanctions motion over fabricated citations actually request?** Ask for what is proportionate to the specific conduct you documented. Three requests tend to be well matched: correction of the record, meaning an order striking or requiring withdrawal of the offending material; fees attributable to the specific work the fabrication caused, supported by time records tied to the defect; and a deterrent sanction where the conduct warrants it, framed in the language the governing rule uses. Three requests tend to hurt: characterizing the entire case or appeal as frivolous, which is the Del Biaggio error and puts your supported request at risk of your unsupported one; terminating sanctions over a citation defect, which reads as disproportionate absent much more serious conduct; and an unsupported dollar figure, which invites the court to substitute a lower number or deny the request outright. A useful discipline is to write the request in one sentence before drafting the argument.
- **Does any of this apply in state court?** The principles travel; the procedure does not. Rule 11 and its 21-day safe harbor are Federal Rules of Civil Procedure and govern federal practice. Del Biaggio and Noland were California appellate matters decided under California rules, including the appellate briefing requirements the Noland court applied in finding the appeal frivolous. A state court may provide a different mechanism, a different notice period, or no safe harbor at all, and appellate practice frequently differs from trial practice within the same jurisdiction. What carries across is the substance rather than the form: verify before accusing, describe the specific conduct rather than characterizing the whole case, ask for relief proportionate to the defect, and build a contemporaneous record of the verification that supports your motion. Confirm the specific procedure governing your matter with counsel before relying on any of this.

## References

- Court of Appeal of California, First Appellate District, Division Four. Del Biaggio v. Bansen, No. A174647 (certified for publication). July 2026. [https://storage.courtlistener.com/pdf/2026/07/10/del_biaggio_v._bansen.pdf](https://storage.courtlistener.com/pdf/2026/07/10/del_biaggio_v._bansen.pdf)
- Court of Appeal of California. Noland v. Land of the Free, L.P. (2025) 114 Cal.App.5th 426. September 2025. [https://law.justia.com/cases/california/court-of-appeal/2025/b331918.html](https://law.justia.com/cases/california/court-of-appeal/2025/b331918.html)
- Legal Information Institute, Cornell Law School. Federal Rule of Civil Procedure 11: Signing Pleadings, Motions, and Other Papers; Representations to the Court; Sanctions. 2026. [https://www.law.cornell.edu/rules/frcp/rule_11](https://www.law.cornell.edu/rules/frcp/rule_11)
- Stanford HAI. AI on Trial: Legal Models Hallucinate in 1 out of 6 (or More) Benchmarking Queries. 2024. [https://hai.stanford.edu/news/ai-trial-legal-models-hallucinate-1-out-6-or-more-benchmarking-queries](https://hai.stanford.edu/news/ai-trial-legal-models-hallucinate-1-out-6-or-more-benchmarking-queries)
- U.S. Court of Appeals for the Ninth Circuit. LNU v. Blanche, No. 24-4790 (9th Cir. June 3, 2026) (published). June 2026. [https://cdn.ca9.uscourts.gov/datastore/opinions/2026/06/03/24-4790.pdf](https://cdn.ca9.uscourts.gov/datastore/opinions/2026/06/03/24-4790.pdf)
- McGuireWoods. California Appellate Court Issues $10K Sanctions in State's First Published Opinion on AI-Hallucinated Case Citations. September 2025. [https://www.mcguirewoods.com/client-resources/alerts/2025/9/california-appellate-court-issues-10k-sanctions-in-states-first-published-opinion-on-ai-hallucinated-case-citations/](https://www.mcguirewoods.com/client-resources/alerts/2025/9/california-appellate-court-issues-10k-sanctions-in-states-first-published-opinion-on-ai-hallucinated-case-citations/)

Written by
## [Jamie Kloncz](https://rankshieldlegal.com/about/)
Founder, RankShield
Jamie Kloncz is the founder of RankShield, the verifiable AI and quantum security platform behind RankShield Legal. An engineer by training, he built RankShield after his own devices and business were attacked, including an AI voice-cloning scam that targeted his family, on one conviction: unverifiable security is the real danger, so every consequential action should leave a receipt anyone can independently check.
[More about Jamie →](https://rankshieldlegal.com/about/)

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Keep reading
## Related guides
[Litigation & Evidence Del Biaggio v. Bansen: Why Cite-Checking AI Is the Lawyer's Job, Not the Paralegal's Read guide →](https://rankshieldlegal.com/blog/lawyer-cite-check-ai-not-paralegal-del-biaggio/)[Citation Integrity Fabricated vs. Misgrounded: The Two Ways Legal AI Gets Citations Wrong Read guide →](https://rankshieldlegal.com/blog/fabricated-vs-misgrounded-legal-ai-citations/)[Citation Integrity How to Verify AI-Generated Case Citations Before You File Read guide →](https://rankshieldlegal.com/blog/verify-ai-case-citations-before-filing/)