In re Marriage of Nash

What sanction did the court impose?

In an unpublished opinion by Judge Grove (Yun and Schock, JJ., concurring), the Colorado Court of Appeals dismissed as untimely the part of the appeal challenging orders issued on or before March 10, 2025, and affirmed the April 14, 2025 award of $1,665 in attorney fees against the father. The court agreed with the district court that "even those citations that were legitimate were not remotely supportive of his legal arguments," and observed in a footnote that, "[a]lthough there is perhaps another explanation for father's citations of nonexistent cases, [...] they bear many of the hallmarks of 'hallucinations' that are a well-publicized problem associated with generative artificial intelligence large language models," citing Al-Hamim v. Star Hearthstone, LLC, 2024 COA 128. Because the mother successfully defended the fee awards, the court granted her request for appellate attorney fees and costs under C.A.R. 39.1 and 39(c)(1) and remanded for the district court to determine the amount.

Why does In re Marriage of Nash matter for law firms using AI?

Marriage of Nash shows the Colorado Court of Appeals addressing possibly AI-generated citations through Colorado’s fee-shifting statute rather than a freestanding sanction. The defective citations appeared in the father’s district-court motion to reconsider its refusal to toll his appellate deadlines. The district court found the cited cases “either [did] not exist, [did] not conclude what [father] states, or [were] not relevant to the issue regarding whether a [d]istrict [c]ourt can toll an appellate deadline,” concluded his motions “lacked substantial justification,” and awarded the mother $1,665 in attorney fees under section 13-17-102. The Court of Appeals reviewed the motion and its citations and agreed.

The opinion’s treatment of AI is careful. It does not find that the father used generative AI. It observes in a footnote that, “[a]lthough there is perhaps another explanation for father’s citations of nonexistent cases,” they “bear many of the hallmarks of ‘hallucinations’” associated with large language models, citing the court’s published decision in Al-Hamim v. Star Hearthstone, LLC. The fee award rested on the broader record: the father had no legitimate authority for his claim that a district court can toll appellate deadlines, misread C.A.R. 4(a)(4) as conferring that power on the district court, and repeated earlier arguments “nearly verbatim.”

The father is a licensed Georgia attorney who represented himself; the opinion does not treat that status as bearing on the fee analysis. The court affirmed the award based on the citations “combined with the history of the case,” so the case illustrates that nonexistent or unsupported citations in a procedural motion can form part of a record that supports fee-shifting for lack of substantial justification, and that a party who successfully defends such an award on appeal may recover appellate fees as well. Firms documenting compliance may wish to consider whether citation verification covers routine motions, not only principal briefs.