hallucination – internetcases – Attorney Evan Brown

A bankruptcy case took a turn during a hearing when the court asked the pro se debtor how he had found the cases he cited in his legal filings. Debtor admitted that he had used artificial intelligence to generate legal arguments and case citations. When the court reviewed those citations, it found they were either misrepresented, irrelevant, or entirely fictitious. One citation led to a case that had been vacated. Another did not say anything close to what debtor claimed. And one did not exist at all.

The court made clear that parties, whether attorneys or pro se litigants, must make a reasonable inquiry before submitting legal contentions to the court. That means personally verifying that cited case law actually supports the argument being made. Using AI without checking the accuracy of the output is not enough.

Even so, the court declined to impose sanctions under the relevant rule. It noted that the case was already being dismissed for independent reasons under bankruptcy law and saw no need to pile on. Essentially, the judge applied a “no harm, no foul” approach. But the warning was clear: AI-generated case law that has not been verified cannot be trusted and will not be tolerated.

In re Perkins, No. 24-32731-thp13, 2025 WL 1871049 (Bankr. D. Or. July 7, 2025)

A federal judge in Wisconsin suspected that one of the parties appearing before the court had used generative AI to write a brief, which resulted in a hallucinated case. The judge issued an opinion with this footnote:

Although it does not ultimately affect the Court’s analysis or disposition, Plaintiffs in their reply cite to a case that none of the Court’s staff were able to locate. ECF No. 32 at 5 (“Caserage Tech Corp. v. Caserage Labs, Inc., 972 F.3d 799, 803 (7th Cir. 1992) (The District Court correctly found the parties agreed to permit shareholder rights when one party stated to the other its understanding that a settlement agreement included shareholder rights, and the other party did not say anything to repudiate that understanding.).”). The citation goes to a case of a different name, from a different year, and from a different circuit. Court staff also could not locate the case by searching, either on Google or in legal databases, the case name provided in conjunction with the purported publication year. If this is, as the Court suspects, an instance of provision of falsified case authority derived from artificial intelligence, Plaintiffs’ counsel is on notice that any future instance of the presentation of nonexistent case authority will result in sanctions.

One must hope this friendly warning will be taken seriously.

Plumbers & Gasfitters Union Local No. 75 Health Fund v. Morris Plumbing, LLC, 2024 WL 1675010 (E.D. Wisconsin April 18, 2024)

Tag: hallucination

Pro se litigant cited AI hallucinated cases but court found no harm, no foul

Footnote in opinion warns counsel not to cite AI-generated fake cases again