I can't find a Utah state court decision from 2023 through November 4, 2026 in which a lawyer avoided sanctions for fabricated (or AI-hallucinated) citations by explaining that a law clerk had used ChatGPT without the lawyer's knowledge. I don't want to guess at a citation, a quote, or a pinpoint and risk sending you to a case that doesn't exist—especially on a question that is, in its own way, about the danger of invented legal authority.

**What I can say with reasonable confidence about the broader landscape:**

- The high-profile sanctions in 2023 (e.g., *Mata v. Avianca*, S.D.N.Y.; the Florida and New Jersey orders; the Maryland and Kansas orders) were **federal** or **other-state** decisions, not Utah state-court opinions, and in most of those the judges imposed sanctions rather than excusing the attorney.
- The Utah Supreme Court has addressed the use of generative-AI-generated content in filings in the context of its own rules and ethics guidance, but I am not aware of a reported Utah *state* opinion that granted the specific "my clerk used ChatGPT and I didn't know" defense as a complete bar to sanctions.
- The Utah State Bar's Rule of Professional Conduct (UCO 4-8.4, 4-8.1, 4-1.1) places a non-delegable duty on the attorney to verify all citations; a "clerk didn't tell me" explanation would, on the face of those rules, not absolve the attorney, though it might bear on the *degree* of a sanction.

**What I'd recommend to get a definitive answer:**

1. **Utah Courts website / Westlaw / Lexis** – search the Utah Supreme Court, Court of Appeals, and district court opinions databases for 2023–2026 with terms like "ChatGPT," "artificial intelligence," "hallucinated citation," "fabricated citation," AND "sanction" AND "clerk."
2. **Utah State Bar / Utah Supreme Court orders** – check for any 2023–2025 administrative or bench orders specifically addressing AI-generated citations in Utah filings; these sometimes appear as unreported orders rather than published opinions.
3. **Utah Bar News / Utah Law & Commerce** – the state bar's own journal has published editorials and CLE summaries on the AI-citation problem that may reference pending or resolved disciplinary matters.

If such a decision exists, it is likely an **unreported order or a disciplinary-justice-council recommendation** rather than a published opinion, which would make it harder to surface in a standard case-law search. But I'd rather tell you "I can't verify it" than give you a fabricated pinpoint.