AI Hallucination Cases

The court found that the majority of legal authorities in appellant counsel's reply brief were incorrect or did not support the propositions for which they were cited. The court struck the reply brief, imposed monetary sanctions of $5,070, and directed a copy of the opinion be forwarded to the State Bar.

Counsel had already been sanctioned in different case, and professed having gone through CLE on generative AI.

The court found numerous quotation and citation inaccuracies in Defendant's Memorandum. Counsel admitted the errors, denied using AI, and the court concluded the errors were negligent violations of Rule 11. The court recommended sanctions including public identification, a $1,500 payment, and oversight measures; the firm must submit a statement of training/oversight.

From the Order to Show Cause (available here): "One week after filing its second motion for summary judgment, Liberty Mutual submitted a notice of errata identifying the erroneous Goodman and Chaudri citations and demonstrating legitimate citations to those cases. [ECF No. 50].3 While the Court acknowledges Liberty Mutual’s prompt notice disclosing the two most serious errors in its filing, the additional misquotations and mischaracterizations discussed above will not be disregarded. Liberty Mutual indicates that the errors were typographical and/or caused by vision impairment, but that explanation is simply not credible. The errors in Liberty Mutual’s filing are not ones in which a few letters or numbers were passed over or shuffled. Rather, the filing includes entire names, dates, court designations, and Westlaw citations that are completely off base, and various other inaccuracies cannot be explained by typographical or vision issues. Therefore, the Court will reserve its ruling on the motion for sanctions and will set a hearing requiring Liberty Mutual to show cause why it should not be sanctioned."

Later on, the court accepted Counsel's technical audit that suggested the errors stemmed from a human, non-AI source.

The Court found 28 false or misleading citations across 11 pleadings (14 fabricated, 14 erroneous/misquoted). Mr. Howie admitted use of ChatGPT and failure to verify citations. The Court applied Rule 11(b) and its AI framework (verification, candor/correction, accountability) and imposed sanctions and restitution. Fines of 3,000, 2,000, and 1,000 USD on individual attorneys, plus opposing party's costs and fees,

Folllowing a show cause order, Counsel admitted to having used the tool together with Google Search, and explained that, although he was aware of the issues with AI models like ChatGPT, he said he did not expect this tool to fall into the same issues.

The Court found Attorney James A. Johnson used Ghostwriter Legal to draft a motion that contained multiple fabricated case citations, misstated/false quotations attributed to authorities, and cited precedent that had been reversed by the Supreme Court. The Court found the conduct tantamount to bad faith and imposed sanctions under its inherent authority. Sanctions include an order to file, not under seal, this order "in any case in any court wherein he appears as counsel fortwelve (12) months after the date of this order."

Show Cause Order is available here.

"When criminal defense attorneys fail to comply with their ethical obligations, their conduct undermines the integrity of the judicial system. It also damages their credibility and potentially impugns the validity of the arguments they make on behalf of their clients, calling into question their competency and ability to ensure defendants are provided a meaningful opportunity to be heard. Thus, criminal defense attorneys must make every effort to confirm that the legal citations they supply exist and accurately reflect the law for which they are cited. That did not happen here."

Counsel admitted he did not verify citations. The court imposed a $1,000 sanction payable personally by counsel, ordered 1 hour CLE on generative AI, and referred him to the Disciplinary Committee.

"In total, appellant's opening brief contains 23 case quotations, 21 of which are fabrications. Appellant's reply brief contains many more fabricated quotations. And, both briefs are peppered with inaccurate citations that do not support the propositions for which they are cited.

[...]

We conclude by noting that "hallucination" is a particularly apt word to describe the darker consequences of AI. AI hallucinates facts and law to an attorney, who takes them as real and repeats them to a court. This court detected (and rejected) these particular hallucinations. But there are many instances-hopefully not in a judicial setting-where hallucinations are circulated, believed, and become "fact" and "law" in some minds. We all must guard against those instances."

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 found Husband's counsel made multiple misleading or incorrect citations and attributed quotations to cases that do not contain them. The court noted some citations used incorrect reporters that pointed to unrelated decisions, concluded the cited authorities did not support counsel's propositions (and in some instances contradicted them), forwarded the decision to the State Bar for possible ethical violations, and awarded costs to the prevailing party.

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.

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.

Counsel admitted his law clerk used AI tools and failed to verify the citations. The court imposed a $2,500 monetary sanction, required completion of CLE in ethics/legal technology, and ordered service of the sanction order to the plaintiff.

Counsel was sanctioned for citing eight nonexistent cases in briefs filed on behalf of his client, in an appeal concerning the termination of parental rights. The court found that Counsel violated Illinois Supreme Court Rule 375 by submitting fictitious case citations generated by AI without verification. As a result, he was ordered to disgorge $6,925.62 received for his work on the appeal and pay an additional $1,000 in monetary sanctions. The court also directed that a copy of the opinion be sent to the Illinois Attorney Registration and Disciplinary Commission.

"The first reason I issue sanctions stems from [Counsel]'s claim of ignorance—he asserts he didn't know the use of AI in general and ChatGPT in particular could result in citations to fake cases. Mr. Nield disputes the court's statement in Wadsworth v. Walmart Inc. (D. Wyo. 2025) that it is "well-known in the legal community that AI resources generate fake cases." Indeed, [Counsel] aggressively chides that assertion, positing that "in making that statement, the Wadsworth court cited no study, law school journal article, survey of attorneys, or any source to support this blanket conclusion."

I find [Counsel]'s position troubling. At this point, to be blunt, any lawyer unaware that using generative AI platforms to do legal research is playing with fire is living in a cloud."

[...]

"If anything, [Counsel]’s alleged lack of knowledge of ChatGPT’s shortcomings leads me to do what courts have been doing with increasing frequency: announce loudly and clearly (so that everyone hears and understands) that lawyers blindly relying on generative AI and citing fake cases are violating Bankruptcy Rule 9011 and will be sanctioned"

In May, the court asked Counsel to show cause why they should not be sanctioned for filing briefs with hallucinations - especially since they continued filing hallucinated submissions after being warned about it.

In their Answer, Counsel revealed that "specific citations and quotes in question were inadvertently derived from internal draft text prepared using generative AI research tools designed to expedite legal research and brief drafting".

In the Order, the court noted that Counsel "was not candid to the Court when confronted about his use of AI, stating that some of these documents were “prepared under time constraints,” when he had nearly two more weeks before the deadline to submit his responses." The judge was also unimpressed by Counsel's attempt to shift the blame to a paralegal.

Finally, in the fee dispute order, the court cited this database to point out that its approach to award costs and fees was appropriate, especially given the egregiousness of the claimant's conduct in this case. The judge also took into account "the significant, if indirect, monetary losses that may arise from nonmonetary sanctions in other cases, such as loss of business and loss of reputation, or the monetary loss borne by a client when a motion or even an entire case is adversely decided due to counsel’s misuse of AI."

Plaintiff's Counsel cited nine non-existent cases in a response to a motion to dismiss, which were generated using AI software. The court found this to be a violation of Rule 11, as the citations were not checked for accuracy. Counsel admitted the error, apologized, and explained the circumstances, including staff transitions and the use of AI. The court imposed a $1000 sanction, required Mr. Braddy to attend a CLE course on AI ethics, and ordered reimbursement of Defendant's attorney fees and costs.

Counsel confessed having Claude Sonnet 4 to draft a legal submission, which included fabricated quotations from legal authorities. Counsel said he was pressed by time.

After holding that there is "no reason to distinguish between the submission of fabricated cases and the submission of fabricated quotations from real cases. In both postures, the attorney seeks to persuade the Court using legal authority that does not exist", the court held that Mr. Desmarais had violated Rule 11 of the Federal Rules of Civil Procedure by failing to verify the accuracy of the AI-generated content. Counsel was found to have acted in subjective bad faith, as he was aware of the potential for AI to hallucinate legal citations and failed to take corrective action even after the government pointed out the errors.

The court imposed a $1,000 monetary sanction and required Counsel to complete a CLE course on the ethical use of AI in legal practice and notify his client of the issue.