Buchanan v. Vuori, Inc.
U.S. District Court, Northern District of California · N.D. Cal. · California bar guidance
Verified April 26, 2026
- Citation
- Buchanan v. Vuori, Inc., No. 23-cv-01121-NC (N.D. Cal. Nov. 20, 2025) (ECF 96)
- Decided
- November 20, 2025
Summary
Plaintiff's solo-practitioner counsel James Dal Bon submitted a corrected motion for preliminary class action settlement approval that cited one nonexistent case, Reed v. ZipRecruiter, Inc., 2021 WL 4453429, and eight fabricated quotations attributed to a real case. Dal Bon admitted using approximately six different AI tools to draft the motion and attempted to use each AI program to verify the others. Magistrate Judge Nathanael M. Cousins found this cross-AI verification was not a reasonable inquiry under Rule 11(b).
- AI tool:
- ChatGPT, Claude, Clear Brief, Lexis, Westlaw (six AI tools per attorney's response)
- Sanction amount:
- $250
What sanction did the court impose?
$250 monetary sanction payable to the Clerk of Court, both motions stricken without leave to refile, and referral to the Northern District's Standing Committee on Professional Conduct under Civil Local Rule 11-6. The court separately found Dal Bon inadequate as class counsel under Rule 23(e)(2)(A), foreclosing any renewed settlement approval motion in his hands.
Why does Buchanan v. Vuori, Inc. matter for law firms using AI?
Buchanan v. Vuori is the broadest multi-vendor AI admission yet recorded in a sanctions order: counsel told the court he ran his draft through roughly six different AI tools, including ChatGPT, Claude, Clear Brief, Lexis, and Westlaw, and used “each artificial intelligence program to check on the other” as his verification procedure. Judge Cousins’s response, that “[u]sing AI to check the work of AI was not a reasonable inquiry,” is the line firms running stacked AI workflows should paste into their written verification policies. The collateral finding, that fabricated citations rendered counsel inadequate under Rule 23(e)(2)(A) and killed the settlement, illustrates that the practical cost of an AI hallucination is rarely the headline dollar sanction; it is the matter, the fee, and the client relationship.
Sources
Primary sources
Further reading
Source PDF is a Westlaw printout mirrored from the Damien Charlotin hallucination database. We are working to add the underlying court docket (PACER, CourtListener, or court website) as a second source.