AI Hallucination Cases

Plaintiff admitted using AI to prepare filings, submitted an unsigned affidavit for a purported attorney and cited cases the court could not locate; court found false statements and potential fake caselaw and ordered show-cause re: Rule 11 sanctions and evidentiary hearing.

Magistrate Judge found Plaintiff's Reply contained multiple citations that do not exist, quotes not found in the cited authorities, and material mischaracterizations of cases; court concluded counsel likely used generative AI and failed to verify outputs and recommended the District Court consider Rule 11 sanctions.

Counsel filed a motion containing case citations that did not exist; counsel admitted the citations were generated by Microsoft CoPilot and not independently verified. The court found a Rule 9011 violation, declined to impose monetary sanctions because of procedural limits and dismissal, and ordered CLE focused on AI ethics.

" Opposing counsel, and the court, should not have to parse case citations and parentheticals to discern whether cases exist, and if so, if they stand for the propositions asserted. "

"Counsel should take seriously its obligation to provide the Court with an accurate description of the law. See, e.g., United States v. Hayes, 763 F. Supp. 3d 1054 (E.D. Cal. 2025) (levying $1,500 in monetary sanctions against counsel personally for fictitious cases and quotations that the court suspected were produced using artificial intelligence),reconsideration denied, No. 2:24-CR-0280-DJC, 2025 WL 1067323 (E.D. Cal. Apr. 9, 2025); Grant v. City of Long Beach, 96 F.4th 1255 (9th Cir. 2024) (striking an appellant's brief and dismissing an appeal for materially misrepresenting or fabricating case citations). After New Materials freely accused opposing counsel of misstating the law, New Materials’ submission of non-existent quotes is troubling (Dkt. 30 at 5 (“Chenco's argument for remand collapses under the weight of its own misreading of the law”); id.at 7 (“Chenco fundamentally misrepresents the applicable removal standard”); Dkt. 34 at 1 (“The proposed sur-reply ... is necessary to address new legal misstatements ....”); id. at 2-3 (“Chenco's failure to address this standard ... misstates controlling law and warrants correction.”)). Accordingly, the Court reminds counsel of their duties to act according to the Idaho Rules of Professional Conduct."

"The case at bar epitomizes the concern. Inordinate judicial resources were expended on reviewing cases cited by Plaintiff that did not exist. No doubt Plaintiff’s opponent in this litigation was forced to expend similar energies. Here, too, as noted, certain cases Plaintiff cited in support of her arguments stood for the opposite result from that which Plaintiff stated in her briefs. This kind of activity not only wastes precious and limited judicial resources, but it also drives up the cost of litigation unnecessarily for those who must defend against or seek to prosecute claims on behalf of paying clients, given the underpinnings of the American Rule that attaches to most civil litigation in this country."

The debtor, Sonja Helvig DeRosa-Grund, engaged in substantial abuse of the Chapter 13 process by filing numerous frivolous motions and making false allegations against opposing counsel. The debtor repeatedly cited non-existent case law and fabricated quotes from existing cases, despite being warned about this behavior. The court dismissed the case with prejudice for one year, terminated the debtor's ECF filing privileges, and imposed additional protective measures to prevent future abuse. The court found that the debtor violated Bankruptcy Rule 9011(b) by making arguments based on non-existent case law and misquoting cases.

The court issued an Order to Show Cause, and the plaintiff's Counsel acknowledged responsibility but did not explicitly admit to using AI. The court determined that the counsel violated Rule 11(b)(2) by failing to verify the accuracy of the citations and imposed several sanctions:

• "The pro hac vice status of Counsel shall be revoked and Counsel will be removed from this case;
• Plaintiff’s Opening Brief shall be stricken;
• Counsel will be ordered to promptly serve a copy of this Order on Plaintiff, who will in turn be afforded time to engage new counsel or proceed as a self-represented litigant;
• Counsel will be ordered to write a letter to the three Judges to whom she attributed fictitious cases, [...], notifying them of her use of fake cases with their respective names attached;
• Counsel will be ordered to transmit a copy of this Order to every Judge who presides over any case in which Counsel is attorney of record; and
• The Clerk of Court’s Office will be directed to serve a copy of this Order on the Washington State Bar Association, of which Counsel is a member. If Counsel is a member of any other state’s bar, she shall serve a copy of this Order on that state’s bar office."

The court imposed sanctions under Rule 11, requiring Mr. Owoc to complete 10 hours of community service and to certify the accuracy of legal citations in future filings if AI is used. No monetary penalty was imposed.

"Second, the protester's explanation--that it was “manual mismatches in secondary summaries” that caused the citation errors (Protester's Resp., Aug. 8, 2025, at 1)--does not meaningfully explain the number of citation errors in the protester's filings. Indeed, Oready's patently erroneous citations are far removed from mere typographical or scrivener's errors, and instead, bear the hallmarks of the use of a large-language model or other artificial intelligence (AI) without adequate verification that the generated results were accurate. "

" We have the authority to sanction Wife under Florida Rule of Appellate Procedure 9.410(a) for failure to comply with Florida Rule of Appellate Procedure 9.210(c). See Gutierrez v. Gutierrez, 399 So. 3d 1185, 1188 (Fla. 3d DCA 2024). However, we decline to do so. Our decision is tempered by the fact that Wife is defending a judgment on appeal in an unrepresented capacity, Husband has not sought the imposition of sanctions, and Wife has not brought any other meritless or frivolous filings in this Court. See id. at 1187–88; Al-Hamim, 564 P.3d at 1125–26. Instead, we admonish Wife for her counterfeit brief and warn her that the Court will not regard similar infractions as mildly in the future. "

"The appearance of hallucinated citations in briefs generated from AI is no longer in its nascent stage. Regrettably, the number and regularity with which courts have been faced with hallucinations in court filings continues to rise both in this country and abroad. See Damien Charlotin, AI Hallucination Cases, (Aug. 6, 2025)https://www.damiencharlotin.com/hallucinations/ (database tracking legal decisions “in caseswhere generative AI produced hallucinated content,” evidencing 255 cases to date) (hereinafter “Charlotin Database”).

[...]

By far, the majority of courts impose sanctions upon the offending lawyer for this sort of conduct and warnings or reprimands have been meted out in cases typically involving pro se litigants. See Charlotin Database, supra. However, there are circumstances where, in the Court’s discretion, monetary sanctions have not been imposed notwithstanding the violation of Rule 11."

Melvin Graham-Jackson, a pro se litigant, filed an appeal with false legal citations in his briefs, citing non-existent legal authorities and unrelated cases. The Court of Appeals identified this as a violation of Wisconsin's appellate rules. Despite being notified of these issues in the respondents' brief, Graham-Jackson continued to use false citations in his reply brief. The court imposed two sanctions: a $500 monetary penalty payable to the defendants to offset their legal expenses, and a requirement for Graham-Jackson to submit an affidavit in any future appeals certifying the accuracy and relevance of his legal citations.

The court imposed a monetary sanction of $1,000 on the appellate counsel and ordered a report to be sent to the Illinois Attorney Registration and Disciplinary Commission (ARDC).

The appellate court dismissed the appeals due to lack of jurisdiction and ordered respondent's appellate Counsel to pay $1,000 in monetary sanctions for violating Illinois Supreme Court Rule 375 by citing multiple cases that did not stand for the propositions of law for which they were cited. The court also ordered a copy of the decision to be sent to the Illinois Attorney Registration and Disciplinary Commission.

Counsel had previously admitted to using AI to prepare briefs in another case (in Re Boy) without thoroughly reviewing the work-product, leading to similar issues. The court found it reasonable to conclude AI was used in this case as well, although not explicitly admitted by Counsel.

"Were Advani a lawyer, the Court would consider imposing sanctions on her. But in view of the fact that she is not a lawyer and of the dismissal of this case, the Court declines to pursue the matter further and merely warns Advani that presentation of false citations, quotations, and holdings in the future may indeed result in the imposition of sanctions."

" According to father, “Welfare and Institutions Code § 350(b) states, ‘Except where otherwise provided by this code, the procedures for the trials or hearings shall be in accordance with that prescribed by law for civil cases.’ ” Section 350, subdivision (b) does not so provide, and we have been unable to verify the legal source for this quotation.3 With respect to Code of Civil Procedure, section 1013, subdivision (a), the statute addresses service by mail, facsimile and electronic service, etc., and provides, in relevant part, for an additional 10 calendar days “if either the place of mailing or the place of address is outside the State of California but within the United States.” "

Footnote 3 then reads:

" Counsel is reminded that conduct of California attorneys is governed by the State Bar Rules of Professional Conduct. In particular, rule 3.3(a)(1) places a duty on counsel not to “knowingly make a false statement of fact or law to a tribunal...,” as does Business and Professions Code section 6068, subdivision (d). This duty is violated when counsel knowingly presents statutory authority to the court that does not exist. A person's “knowledge” under this rule may be inferred from the circumstances. (Rules Prof. Conduct, rule 1.0.1(f).) Moreover, the inclusion of nonexistent legal authority may also be considered a “matter [that is] not reasonably material to the appeal's determination.” (Cal. Rules of Court, rule 8.276(a)(2).) Failure to adhere to these standards of practice and rules may result in sanctions which themselves may be mandatorily reportable to the California State Bar. (Bus. & Prof. Code, § 6068, subd. (o)(3).) "

After being ordered to show cause, Counsel submitted a brief that compounded the issue.

"The Court was dismayed to see that some of the discussion/analysis provided by Mr. Chinweze appeared to be from artificial intelligence generated case summaries which was indicated by the inclusion several times of the statement that "Some case metadata and case summaries were written with the help of AI." Another indication that the paragraphs of discussion/analysis were copied from another source or were generated by AI is that several paragraphs have superscript for footnotes, but no footnotes are found on any page of the Appendix."

The court then cited this database to highlight the growing problem of hallucinations in legal cases.

Counsel was ordered to pay 1,000 USD to the Lawyers Fund for Client Protection, and he was referred to the bar authorities.

The debtor, Ryan Lashon Ford, appeared pro se in a bankruptcy case and was found in civil contempt for failing to comply with court orders. The debtor cited non-existent legal authorities, such as 15 U.S.C. § 114, which the court identified as fabricated citations.

The court also encouraged, but did not require, Plaintiffs' counsel to complete a CLE course on LLMs and legal ethics.