Cartagena v. Dixon
U.S. District Court, Southern District of New York · S.D.N.Y. · New York bar guidance
Verified April 26, 2026
- Citation
- Cartagena v. Dixon, No. 1:25-cv-03552-JLR, ECF No. 161 (S.D.N.Y. Mar. 10, 2026)
- Decided
- March 10, 2026
Summary
Defense counsel Tyrone A. Blackburn, representing himself and his firm T.A. Blackburn Law, PLLC against a defamation suit brought by recording artist Joseph Cartagena (Fat Joe), filed a Rule 12(b)(6) motion to dismiss containing pervasive citations to non-existent authority and misrepresentations of law. Blackburn attributed the fabricated citations to LexisNexis's "Protégé" AI research platform, but LexisNexis submitted a letter to the court refuting that he had any subscription to Lexis+ AI or Protégé. Judge Jennifer L. Rochon catalogued Blackburn's prior sanctions and warnings, including the October 2025 Rule 11 sanction in Jakes v. Youngblood (W.D. Pa.), an earlier Grievance Committee referral by Judge Denise Cote in Zunzurovski v. Fisher, a 2025 warning by Judge J. Paul Oetken in Jones v. Combs, and a September 2025 New York state court order in Facey v. Fisher requiring Blackburn to explain repeated citations to nonexistent cases.
- AI tool:
- Protégé (LexisNexis) (claimed; LexisNexis disputes Blackburn had access)
What sanction did the court impose?
Public admonition only. The court declined to strike Defendants' submissions or award attorneys' fees, but issued a "lengthy historic recitation" of Blackburn's prior misconduct as a "public admonition aimed to deter future misconduct" and warned that further misconduct may lead to sanctions or a referral for discipline. The court separately denied Blackburn's own Rule 11 sanctions motion against Cartagena.
Why does Cartagena v. Dixon matter for law firms using AI?
Cartagena v. Dixon is the third documented AI-hallucination sanctions episode for attorney Tyrone A. Blackburn within roughly five months, following Jakes v. Youngblood (W.D. Pa. Oct. 6, 2025) and Gardner v. Combs (D.N.J. Dec. 15, 2025). Two features distinguish this order from the prior two. First, Judge Rochon imposed no monetary sanction and no discipline referral, electing instead a public admonition that catalogues five prior judicial findings of misconduct (Cote, Oetken, Stickman, the New Jersey court, and a New York state court). Second, the court flagged a separate factual concern: Blackburn told the court the fabricated citations came from LexisNexis’s Protégé tool, but LexisNexis filed a letter stating he had no subscription to that product, raising a misrepresentation question independent of the AI hallucinations themselves. For managing partners, the case underscores that “I used an AI tool” is not a self-executing mitigation: the court will verify the claim with the vendor, and an unverified or false attribution to a specific platform compounds the underlying citation failure.
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.