David R. Cooper's Legal Matter Status After Sanction

For the search “Jonathon Cooper legal matter status update,” the sanctions record points to David R. Cooper, not Jonathon Cooper, the Denver Broncos linebacker. David R. Cooper is the Kansas defense lawyer sanctioned in a federal patent case over a brief containing ChatGPT-hallucinated citations. The matter was Lexos Media IP LLC v. Overstock.com Inc. in the U.S. District Court for the District of Kansas.

The short status is this: on February 2, 2026, Cooper was fined $1,000, the smallest monetary sanction imposed on the lawyers addressed in the same order, after the court found that his review of a brief he signed did not satisfy Rule 11 and local-counsel obligations in D. Kan. Rule 83.5.4.[1][2] As of July 29, 2026, his public professional record still shows him as a partner at Fisher Patterson Sayler & Smith LLP, a member of the Kansas Board of Law Examiners, and a Best Lawyers 2026 Lawyer of the Year honoree.[3] The underlying patent case did not remain pending around the sanctions issue: Overstock obtained summary judgment on all claims on March 10, 2026.[4]

What Cooper Was Sanctioned For

Cooper’s sanction was not reported as a finding that he personally prompted ChatGPT or generated the defective authorities. His exposure came from a different and more ordinary litigation act: he signed a brief as local counsel after reading it, without independently verifying the cited authorities.

That distinction matters. Local counsel in a federal case is not just a mailing address or a ceremonial signature. In the District of Kansas, D. Kan. Rule 83.5.4 requires meaningful participation by local counsel. In the court’s view, as reproduced in Supreme Today AI’s account of Judge Julie A. Robinson’s order, Cooper’s reading of the brief did not meet that standard because he did not check whether the citations said what the brief claimed they said.[5]

The defective brief reportedly contained three kinds of citation problems: cases that did not exist, quotations attributed to real cases but not found in those cases, and real cases cited for propositions opposite to what they actually held.[1][5] A fabricated example identified in reporting was Hockett v. City of Topeka, which appeared as though it were a real authority.[5]

Those categories are useful because they show why a visual read-through was not enough. A nonexistent case may look conventionally formatted. A fake quotation may sit comfortably inside a familiar string cite. An inverted holding may be harder to catch than a fake case because the case itself is real. Each defect requires some form of source verification, not just familiarity with the brief’s argument.

The aggravating point was that Cooper had already encountered a citation problem earlier in the same case. Supreme Today AI’s reproduction of the order reports that Cooper had previously caught a similar citation error, which made later non-verification harder to treat as an innocent failure of imagination.[5] After that warning sign, the court expected more than reading for sense, tone, and litigation strategy.

Why Reading the Brief Did Not Satisfy the Court

Rule 11 problems are often discussed as if the only risky conduct is inventing law or submitting a filing in bad faith. The Cooper sanction sits in a narrower lane. The court treated the signature itself as a representation that the legal content had been reasonably investigated. For a local lawyer admitted in the forum, that responsibility did not disappear because other lawyers drafted the argument.

The practical standard is blunt: if a lawyer signs a brief, and the brief relies on authorities, the lawyer needs a reasonable basis to believe those authorities exist and support the stated propositions. A lawyer may divide labor with co-counsel, but the division cannot reduce local counsel’s role to proofreading.

That is why the sanction does not turn on whether Cooper was the principal architect of the AI use. The court’s concern was the absence of independent cite-checking at the point when his signature made him responsible for the filing. The earlier citation issue in the case sharpened that duty because it put the risk in plain view before the sanctioned brief reached the court.

The Sanction Was Real, but It Was Not the Largest Penalty

Cooper’s $1,000 sanction was the smallest of four monetary sanctions described in the February 2026 coverage. Richard J. Seth was sanctioned $5,000, had pro hac vice admission revoked, and was referred for possible discipline; Joe and Kula were fined $3,000 each; another lawyer, Doell, was admonished but not fined.[1][2]

The dollar amount should not be inflated into a professional death sentence, but neither should it be treated as a clerical footnote. A court-imposed sanction for an inadequate Rule 11 review is a material litigation-support fact. It belongs in conflicts, staffing, and AI-use risk discussions precisely because it identifies a breakdown in the filing-control process.

Norton Rose Fulbright later reported that Fisher Patterson adopted a formal firm-wide policy prohibiting generative AI use without client consent, and that Cooper voluntarily stopped sponsoring pro hac vice admissions for 12 months.[6] Those measures are not the same thing as a disciplinary suspension. They are better read as risk controls and professional-positioning responses after a public sanctions order.

Current Professional Status as of July 29, 2026

Cooper’s Fisher Patterson profile remained publicly available on July 29, 2026, listing him as a partner of the firm. The same profile identified him as serving on the Kansas Board of Law Examiners and as Best Lawyers 2026 Lawyer of the Year.[3]

Those public listings answer only the public-status question. They do not prove that there were no private client consequences, internal firm restrictions, insurance discussions, engagement-letter changes, or reputational effects. They do show that, as of the stated date, the publicly verifiable record did not show Cooper removed from his partnership, removed from the Kansas Board of Law Examiners, or stripped of the listed Best Lawyers recognition.

Where the Underlying Patent Case Ended

The sanctions order did not decide the patent merits. The underlying case concerned Lexos Media’s claims against Overstock involving cursor-related patent issues. On March 10, 2026, the Kansas court granted summary judgment for Overstock on all claims, according to PatSnap’s litigation coverage.[4]

For a status memo, that separation is important. Cooper’s sanction concerned the integrity of a filing process. The later summary judgment resolved the case outcome in Overstock’s favor. One does not erase the other; they answer different questions.

How This Fits the 2026 AI-Sanctions Pattern

The Cooper matter was not an isolated judicial irritation with legal AI. Norton Rose Fulbright’s 2026 update, citing Damien Charlotin’s database, reported at least 1,148 hallucination cases involving U.S. lawyers as of early 2026, and stated that sanctions in the first quarter of 2026 exceeded $145,000.[6] Those figures describe a dated risk environment, not the exact count as of July 2026.

The point for counsel is not that every use of generative AI leads to sanctions. The point is that courts are increasingly treating the verification step as the lawyer’s work, regardless of whether the defective text began with an associate, co-counsel, a vendor tool, or a public chatbot.

The Status Update in One Record

David R. Cooper was sanctioned $1,000 because the court found that his signature on a brief with unverified AI-hallucinated citations did not satisfy Rule 11 and D. Kan. Rule 83.5.4 meaningful-participation obligations. The key failure was not merely that bad citations appeared; it was that a lawyer who signed the brief did not independently verify them, even after an earlier citation problem had surfaced in the same case.

As of July 29, 2026, Cooper remained publicly listed as a Fisher Patterson partner, Kansas Board of Law Examiners member, and Best Lawyers 2026 Lawyer of the Year honoree. The underlying Lexos v. Overstock patent case ended with summary judgment for Overstock on March 10, 2026.

References

1. 4 Attys Sanctioned Over AI Hallucinations In Legal Brief, Law360
2. Judge fines lawyers $12,000 over AI-generated submissions in patent case, Reuters, February 3, 2026
3. David R. Cooper, Fisher Patterson Sayler & Smith LLP
4. Kansas Court Grants Summary Judgment for Overstock, PatSnap
5. District Court Sanctions Attorneys for Unverified AI-Generated Fake Citations, Supreme Today AI
6. AI in litigation: Update on Gen AI sanctions in 2026, Norton Rose Fulbright