Hildebrandt v. siParadigm LLC
U.S. District Court, District of New Jersey · D.N.J. · New Jersey bar guidance
Verified April 26, 2026
- Citation
- Hildebrandt v. siParadigm LLC, No. 2:23-cv-21835 (D.N.J. Dec. 31, 2025) (Semper, J.)
- Decided
- December 31, 2025
Summary
Plaintiffs' counsel filed a supplemental brief in opposition to defendants' motion to strike or dismiss the consolidated complaint that Judge Jamel K. Semper found "rife with unchecked AI use and replete with incorrect quotations and citations." The court documented forty-three separate instances of fabricated case law or misquoted citations within the single supplemental filing. The court declined to consider the supplemental filing, noting it was both untimely and pervaded by hallucinated authority.
- AI tool:
- Unspecified generative AI
What sanction did the court impose?
The court refused to consider plaintiffs' supplemental filing on its merits and rejected it as both untimely and unreliable due to the volume of AI-generated fabrications. Specific monetary sanctions and any bar referral are not independently confirmed from the order text accessible to this entry.
Why does Hildebrandt v. siParadigm LLC matter for law firms using AI?
Hildebrandt is a useful counterweight to the single-citation hallucination cases that dominate the 2024-2025 sanctions docket. When a court documents forty-three fabrications in one supplemental brief, the failure is no longer a missed verification step; it is a workflow that never included verification at all. For a managing partner, the operational lesson is that any associate or contract attorney permitted to file under the firm’s name needs an enforced cite-check pass, and “supplemental” or last-minute filings deserve more scrutiny, not less.
Sources
Primary sources
Further reading
- Document mirror (Damien Charlotin hallucination database, Westlaw printout)
- Justia (legal aggregator)
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.
- The PDF copy of the order hosted on Charlotin's S3 mirror returned binary/encoded content that could not be reliably text-extracted in this verification pass, so the sanctioned attorney's name, the specific AI tool (if named in the order), and any monetary sanction amount could not be confirmed from the primary document. The forty-three-instance count and Judge Semper's "rife with unchecked AI use" quotation are sourced from secondary reporting consistent with the docket and date.