AI Hallucination Cases

The appellate opinion and editor's note identify numerous incorrect or non-existent case citations in the appellant's filings. The court treated those citations as unreliable, found several to be fictitious or unlocatable, and declined to credit them in resolving the appeals.

Case dismissed for "good cause" in light of motions to dismiss expert. Expert had confessed using ChatGPT.

CC cited a fictitious AI-generated case in written submissions. The Defendant's counsel located the error, CC admitted the authority was AI-generated and did not exist, and the Court found CC acted improperly, ordering personal costs of $800.

The appellant's original factum contained references to seven cases that could not be located (six allegedly decisions of this Court). Respondent flagged the issue; appellant's counsel ultimately acknowledged a contractor-drafted factum and that a large language model may have been used. The Court allowed an amended factum and reserved costs, warning that use of LLM without verification may attract costs, contempt proceedings, or Law Society referral.

Actually the fourth order in that case that pertains to hallucinations; a first, June 5 Order is only mentioned in a second, June 18 order that does not call out what appears to be hallucinated references.

The district court independently found numerous inaccurate quotations and citations in Plaintiff's Opposition—misquoted language attributed to binding Third Circuit authority, Westlaw citations and dates that were incorrect or non-existent, and miscited pincites. The court concluded the pattern suggested the brief may have been prepared using generative AI without adequate verification and ordered counsel to show cause under Rule 11 and ethical rules. The court preserved the inaccuracies in the official opinion but removed links to invalid citations.

Story available here.

Plaintiff's counsel admitted that the opening memorandum and reply brief contained false AI-generated content. Counsel filed corrected memoranda; the court noted a Rule 11 violation but accepted the corrections and declined to impose sanctions or require additional briefing.

The Court preserved the invalid citations in the opinion as they are part of the record, admonished that fabricated or incorrect citations frustrate review and may lead to reprimand or sanction.

In the Order, the court stated: "A simple Google search would have shown the problems in some of Plaintiffs’ citations. In other instances, a quick search of the opinion Plaintiffs cited to would have revealed problems. Levying appropriate sanctions here promotes deterrence without being overly punitive, as contemplated by Rule 11(c)(4).

The Court notes that, rather than showing contrition, the Memorandum in Compliance strikes a defiant and deflective tone. (Docket No. 190). It also contains more of the errors that plagued Plaintiffs’ previous four filings. For example, in the “Legal Standard” section of the memorandum, Plaintiffs cite to two cases for the proposition that sanctions are an “extreme remedy” appropriate for instances of prejudice or bad faith. One case makes no mention of sanctions and neither contain the proffered quote Id. at 3. The Court finds it problematic that Plaintiffs responded to a show cause order to address the problem of multiple inaccurate citations by providing a response containing more erroneous citations."

Monetary sanction was decided in a subsequent decision dated 23 September 2025, available here.

Case involved counsel sanctioned in Coomer v. Lindell. In the OSC Order, the court noted:

"The fact that Kachouroff and DeMaster corrected some of their misrepresentations before the court or the defendants identified them would ordinarily mitigate their conduct. But the reality is that Kachouroff and DeMaster acted only after the Colorado District Court in Coomer v. Lindell noted similar misconduct. That so many misrepresentations persist supports the inference that counsel’s conduct was not mere negligence but an intentional effort to mislead the court."

In her response to the OSC, Counsel disclosed the Westlaw tools she had used.

"The Court respectfully proposes that the time may be near for an exception to the Erickson liberal-construction rule, where a pro se individual relies on AI to draft pleadings and thus blurs the line between what is a good faith pro se assertion of an actionable claim and what is a computer-generated morass that only serves to waste court time and resources."

Defendant's reply brief contained citations that did not support her arguments and included at least one non-existent case citation; the court concluded these errors suggest use of AI and treated the issues as abandonment under Rule 28(b)(6), dismissing the appeal.

The court found the plaintiff's filings contained misrepresentations of the record—specifically, a purported 'Clerk's Entry of Default' that never existed and a claim that an Immigration Judge made a final binding APA finding. The court attributed these misrepresentations to likely AI generation, warned the plaintiff about consequences for false statements, and construed the misrepresentations as AI misapplication rather than deliberate deception.

The appellant (self-represented) cited two nonexistent cases in her appellate brief. The respondent flagged the fictitious citations and requested sanctions. The court found the citations fictitious, discussed sanction authority and AI-generated filings, but declined to impose sanctions because the request was procedurally inappropriate, the appellant corrected filings promptly, and the legal propositions were, in fact, supported by existing authority.

"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 appellate court observed that the pro se appellant's opening brief cited cases that do not exist and exhibited hallmarks of generation by a large language model (repetitive 'refined' drafts, internal suggestions, and the statement 'Generative AI is experimental'). The court identified the fabricated citations and noted the brief's deficiencies but proceeded to decide the jurisdictional timeliness issue on the merits, affirming dismissal.

The appellant admitted using generative AI to prepare his Notice of Appeal and Summary of Argument. The Court found several cited authorities could not be located (concluding they were fictitious) and held that deploying unverified AI-generated research that cites non-existent cases breaches duties not to mislead the court and risks contravening Pt XIVB of the Family Law Act 1975 (Cth) (on confidentiality of proceedings).