Lopez v. Mead Johnson Nutrition Company
U.S. District Court, Northern District of California · N.D. Cal. · California bar guidance
Verified May 5, 2026
- Citation
- Lopez v. Mead Johnson Nutrition Co., No. 24-cv-03573-HSG, 2026 WL 788492 (N.D. Cal. Mar. 20, 2026)
- Decided
- March 20, 2026
Summary
Defense counsel from Tucker Ellis LLP, representing Mead Johnson Nutrition Company, included a fabricated quotation attributed to Becerra v. Dr Pepper/Seven Up, Inc., 945 F.3d 1225, 1228 (9th Cir. 2019) in their motion to dismiss briefing. The brief quoted the case for the premise that "[c]ommon law claims for fraudulent and negligent misrepresentation are analyzed" under the same "reasonable consumer" framework. Judge Haywood S. Gilliam, Jr. found that the partial quotation did not appear in the cited opinion and that Becerra did not involve those causes of action. The order does not name a specific AI tool, but the fabricated quotation pattern is consistent with generative AI hallucination.
- AI tool:
- Unspecified generative AI
What sanction did the court impose?
Judge Gilliam granted the motion to dismiss without leave to amend, then issued an order to show cause directing defense counsel to file a statement of two pages or less by March 27, 2026 explaining why they should not be sanctioned for the inaccurate quotation. The court cited Oneto v. Watson, 808 F. Supp. 3d 974 (N.D. Cal. 2025), noting that courts have sanctioned attorneys nationwide for submitting fictitious case citations and quotations.
Why does Lopez v. Mead Johnson Nutrition Company matter for law firms using AI?
Lopez v. Mead Johnson illustrates that hallucination risk is not confined to plaintiff’s solo practitioners or pro se filers. Tucker Ellis LLP is a national defense firm, and the fabricated quotation surfaced in routine motion-to-dismiss briefing in a consumer class action. For managing partners, the case is a reminder that verification protocols must apply to every brief, including those drafted by experienced associates at established firms, and that an order to show cause can issue even when the underlying motion is granted.
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.