A federal court fined a lawyer $6,000 for a brief built on an AI-hallucinated case

The problem

Tyrone A. Blackburn represented plaintiff Liza Gardner in her civil suit against Sean “Diddy” Combs and others, opposing the defendants’ motions to dismiss (source). His brief “cited to a non-existent case” and “fabricated legal propositions derived from generative artificial intelligence” (source). After the court’s inquiry, it issued an order to show cause why Blackburn should not be sanctioned under Rule 11 (source).

What was built

Nothing was built here: this is an AI-governance honest-negative, an unnamed generative-AI tool used as a drafting aid without a verification step. The order records that Blackburn “cited to a non-existent case (‘United States v. Masha, 990 F.3d 1005, 1014 (7th Cir. 2021)’)” in support of the opposition to the motions to dismiss (source). Blackburn “confirmed that he indeed used AI that provided him with hallucinated case law and propositions that he then incorporated into his response brief and that he failed to verify on subsequent review” (source). Bloomberg Law reported the same, that Blackburn “relied on the non-existent case United States v. Masha to argue against dismissing UMG from the case” (source). The order attributes the fabrication generically to generative AI and names no product (source).

The outcome

The number that gets quoted: a $6,000 Rule 11 sanction, paid at $500/month. On December 15, 2025, Leo M. Gordon, Judge, a U.S. Court of International Trade judge sitting by designation in the District of New Jersey, found that “Mr. Blackburn’s conduct plainly violated Rule 11” (source). The order states that “Plaintiff’s counsel, Mr. Blackburn, is sanctioned with a fine of $6,000.00 under Rule 11(c), to be made payable to the registry of this Court at a rate of $500/month” (source). Bloomberg Law and Law360 both report the $6,000 fine and the $500 monthly schedule beginning in March (source).

Non-monetary sanctions on top of the fine. The court ordered Blackburn to “self-report the OSC and this Opinion and Order to the appropriate attorney licensing entities of the States of New Jersey and New York,” and to serve and discuss the order with his client (source). The court weighed a prior AI-related Rule 11 sanction against Blackburn in a “related matter,” Jakes v. Youngblood, Case No. 2:24-cv-01608-WSS (Western District of Pennsylvania), “for similar AI-related citation and quotation errors” (source).

The sanction still stands. In a May 11, 2026 hearing, Judge Gordon held Blackburn in contempt for failing to make the first installments but issued only an oral admonition after new counsel agreed to arrange payment; the $6,000 fine was not vacated or reduced (source).

How this was verified

The origin is a published federal court order, which is self-authenticating: no client-confirmation call is booked against the court, and green here never depends on the sanctioned attorney confirming anything (source). Checked live on 2026-08-14, the order’s own text was read for the $6,000 fine, the $500/month registry schedule, the “United States v. Masha” citation and Blackburn’s admission that he used AI and failed to verify it, and each was corroborated by two mutually independent newsrooms, Bloomberg Law and Law360 (source). The honest limit: the specific AI product Blackburn used is not named in the order, and no claim in this file asserts one (source).

Related case files

This is the second Rule 11 sanction against the same lawyer: the court cited his earlier Jakes v. Youngblood sanction in the Western District of Pennsylvania as the pattern that pushed the fine higher. The pattern continued in Dixon v. Cartagena, where the same attorney had AI-fabricated quotations struck and drew a grievance referral in the Southern District of New York. The order also benchmarked its fine against OTG v. Ottogi, another District of New Jersey Rule 11 sanction for AI-fabricated citations, which shows the range these fines are drawn from.

Sources

Cited in this case file. Tier 1 = the primary court order; Tier 2 = independent press naming the parties. Figures checked live on 2026-08-14 against the order’s own text and the two newsrooms below.

1. U.S. District Court, District of New Jersey, “Opinion and Order,” Gardner v. Combs, No. 2:24-cv-07729-LMG-JRA, ECF No. 92, 2025-12-15 (Tier 1, primary; opinion by Leo M. Gordon, Judge). https://www.govinfo.gov/content/pkg/USCOURTS-njd-2_24-cv-07729/pdf/USCOURTS-njd-2_24-cv-07729-3.pdf
2. Bloomberg Law, “Attorney in Diddy Case Risks Contempt for AI Citation Blunder,” 2026 (Tier 2, independent press naming the parties). https://news.bloomberglaw.com/litigation/attorney-in-diddy-case-in-trouble-for-ai-fake-citation-blunder
3. Law360, “Combs Accuser’s Atty Avoids Jail For Overdue AI Fine,” 2026-05-11 (Tier 2, independent press, reports the contempt finding that left the sanction standing). https://www.law360.com/articles/2475885/combs-accuser-s-atty-avoids-jail-for-overdue-ai-fine