A Utah judge fines BYU's outside lawyers $3,000 over AI-hallucinated briefs

September 2026 — A federal judge in Utah sanctioned two lawyers for Brigham Young University after their briefs cited a case that does not exist. Here's what happened, what it cost, and what went wrong.

Cost and outcome (as of Sept. 9, 2026)

Outcome: Judge Ted Stewart found both lawyers violated Rule 11(b) by failing to check "the existence and accuracy of the legal authority cited." (Sanctions order)
Cost: Pehrson must pay $2,000 and complete two CLE courses on the ethical use of AI within six months; Clark must pay $1,000. (Sanctions order)
Fees: counsel said they had refunded opposing counsel's legal fees caused by the errors; the amount is not stated. (Sanctions order)
Status: proof of payment is due within 30 days of the Sept. 9 order. (Sanctions order)

The briefs

The case was filed in 2012, its docket number shows. The current fight is over an arbitration about research credit. In a brief filed Feb. 3, 2026, BYU said a three-arbitrator panel had ruled in December 2025 that Dr. Robertson "made no qualifying contributions to the COX-2 discovery," and it opposed a motion by the Donald L. Robertson Trust to vacate that decision. A second brief, filed the same day, asked the court to confirm the award.

Both list Pehrson, of KNH LLP, and Clark, of Parr Brown Gee & Loveless, as BYU's attorneys; Pehrson's is the only electronic signature, the filings show.

What the judge found in them

In a July 30 order, Stewart wrote that the filings "are riddled with what appear to be AI hallucinated errors."

BYU's brief said "[v]acatur requires egregious misconduct" and cited a 1997 Tenth Circuit decision. That case "does not contain the terms 'egregious' or 'misconduct,'" the judge wrote. A Supreme Court case cited for the same point does not either, he said.

One citation, "Scandinavian Reins. Co. v. Emp'rs Reins. Corp.," "is not an existing case," the order says. The reporter citation belonged to an immigration appeal from the Ninth Circuit.

The judge said some errors were "of particular concern" because they "purport to establish the controlling law of the dispute." He ordered the lawyers to explain why BYU's opposition should not be struck and the trust's motion treated as unopposed.

Two different explanations

Before the court acted, Pehrson filed a notice of errata on May 22 correcting the citations. It said counsel "takes full responsibility for these unfortunate errors which were the result of counsel's insufficient cite checking procedures, independent of the use of computer-assisted technology."

At the Sept. 2 hearing, the account changed, according to the sanctions order. Pehrson said he drafted the briefing and "relied on several AI models in drafting the briefing, including ClearBrief, Claude, ChatGPT, and Gemini." He said the errors came from "his failure to review the accuracy of the legal contentions." Clark said he did not review the filings either and had enrolled in a CLE course on AI in law.

The judge credited them for having "accepted responsibility" and for repaying fees. "The Court takes misuse of AI, and the harm flowing therefrom, very seriously," he wrote. He quoted Mata v. Avianca, a 2023 New York ruling, which said fake opinions promote "cynicism about the legal profession and the American judicial system."

What went wrong

Four tools, no check. The lawyer who drafted the briefs used several AI models and did not verify what they produced, the order says.
A second listed lawyer didn't read it. Clark told the court he did not review the filings before they were submitted.
The first explanation left AI out. The errata described the errors as "independent of the use of computer-assisted technology."
What we don't know yet: how much in fees was refunded, how the court will rule on the trust's motion, and whether either firm changed its review rules.

Our follow-up question for KNH LLP and Parr Brown Gee & Loveless

What review now has to happen before an AI-assisted brief is filed under a partner's signature?

Sources

U.S. District Court for the District of Utah, Judge Ted Stewart, “Memorandum Decision and Order Imposing Sanctions,” Beus Gilbert PLLC v. Brigham Young University, No. 2:12-cv-00970-TS, Doc. 385, Sept. 9, 2026. storage.courtlistener.com
U.S. District Court for the District of Utah, Judge Ted Stewart, “Order to Show Cause,” Doc. 380, July 30, 2026. storage.courtlistener.com
KNH LLP for Brigham Young University, “Notice of Errata Regarding ECF No. 375 and ECF No. 376,” Doc. 378, May 22, 2026. storage.courtlistener.com
Brigham Young University, “Memorandum in Opposition to Trust's Motion to Vacate,” Doc. 375, Feb. 3, 2026. storage.courtlistener.com
Brigham Young University, “Reply in Support of Motion to Confirm Arbitration Decision and for Entry of Final Judgment,” Doc. 376, Feb. 3, 2026. storage.courtlistener.com

Disclosure: [not in copy] Editor placeholder