California Appellate Court Delivers State’s First Published Ruling On AI-Hallucinated Citations In Legal Pleadings, Declares Issue of First Impression and Warns Attorneys with $10K Sanction

The panel emphasized that while other state and federal courts have begun addressing AI hallucinations in court filings, this represents “an issue of first impression in California state court.”

“We therefore publish this opinion as a warning,” the judges declared. “Simply stated, no brief, pleading, motion or any other paper filed in any court should contain any citations — whether provided by generative AI or any other source — that the attorney responsible for submitting the pleading has not personally read and verified.”

Defense attorney Michael Yadegari of Yadegari & Associates, who represented Nazar, characterized both the appeal and the underlying 2018 case as frivolous.

“I won a very hard case, and it was a long time coming,” Yadegari said Monday. “I told [Mostafavi] in the beginning the case was frivolous, and he was making up stuff and sending me these massive briefs with tons of pages and I don’t think he checked the cases.”

The panel consisted of Justices Lee Smalley Edmon and Anne H. Egerton, along with Riverside County Superior Court Judge Kira Klatchko sitting by designation.