AI Hallucination Cases

Appellant Father's counsel submitted an opening brief containing misleading/inaccurate legal citations, mischaracterized case law, fabricated quotations attributed to Owen v. Blackhawk, and false quotations purportedly from the amended decree and hearing transcripts. The appellate court identified these errors, concluded they supported a potential ethics referral, and forwarded the decision to the State Bar for review.

The plaintiff's sworn declaration contained multiple fabricated quotations and manufactured deposition citations. Defendants identified the fabrications in a motion to strike; the court found the declaration filed in bad faith, struck it, and imposed sanctions under Fed. R. Civ. P. 56(h). The plaintiff admitted using generative AI to draft portions and failing to review the declaration; counsel failed to verify the citations despite attending and taking the depositions.

Amazon alleged that Allen's undisclosed use of AI produced non-existent case citations and hallucinated quotations; the court declined to sanction, warned Allen and required future compliance with local AI-disclosure rule.

"Mr. Obermann’s submissions refer to cases that do not exist or do not apply. I find the most likely explanation is that they are “hallucinations” generated by artificial intelligence. In AQ v. BW, 2025 BCCRT 907 at paragraph 16, a CRT vice chair found that CRT’s obligation to provide sufficient reasons did not require it to address arguments with no basis in law. I agree with this reasoning and do not address those cases. "

The court also identified five other cases in which the same firm or attorney confessed having misused AI. This despite the attorneys attending CLE training

Order to show cause is here.

MIO produced a prolix Defence containing multiple non-existent, miscited and misapplied authorities. The Court found AI-driven research produced hallucinatory results and that MIO failed adequately to verify authorities, amounting to reckless conduct warranting an indemnity costs order.

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.