Adams v. Kiewit Infrastructure West Company
U.S. District Court, District of Arizona · D. Ariz. · Arizona bar guidance
Conduct
A pro se plaintiff's motion to amend cited an Arizona case that does not exist and a Ninth Circuit case at a reporter cite belonging to an Eleventh Circuit case.
Consequence
Motion struck on Local Rule grounds; the court inferred AI use and warned that future hallucinated cases will result in sanctions.
Lesson
Here the court treated AI use as not necessarily a problem, but put the pro se filer on notice that unverified citations will be sanctioned next time.
Verified September 29, 2026
- Citation
- Adams v. Kiewit Infrastructure West Co., No. CV-25-01823-PHX-DJH, Order (D. Ariz. Apr. 29, 2026) (Humetewa, J.), ECF No. 41
- Decided
- April 29, 2026
Summary
Bathsheba Nichole Adams, representing herself in an action against Kiewit Infrastructure West Company and other defendants, filed a Motion for Leave to File Revised Second Amended Complaint on April 24, 2026. Judge Diane J. Humetewa found the motion non-compliant with Local Rule 15.1(a), because the proposed pleading did not show how it differed from the one it would amend, and noted there was no sign Adams had met and conferred with defendants. The court also observed that a complaint is not the place for legal authority and that Adams had been told three times that she must follow the Local and Federal Rules. "On a related note," the court found that her filing "contained several troubling errors." It cited "Ellsworth v. Am. Arbitration Ass'n, 148 Ariz. 17, 19 (App. 1985)," but "no such case exists"; the court found only a Utah case of that name at 148 P.3d 983. It also cited "Aguilar v. ASARCO" at 780 F.3d 1101, but no Ninth Circuit case of that name exists there; that citation belongs to an Eleventh Circuit case, Lary v. Trinity Physician Financial & Insurance Services.
- AI tool:
- Generative AI, by inference (the court: "These hallucinations allow the Court to infer that Plaintiff prepared her filing with the use of generative artificial intelligence"; no tool named)
What did the court warn about?
The court struck the motion from the record, on the stated ground that it did not comply with the Local Rules of Civil Procedure. On the citations, it inferred from the hallucinations that Adams prepared her filing with generative AI, and explained that "the use of such a tool is not necessarily problematic, the failure to confirm the accuracy of the filing is." Rule 11, it stated, makes the signer's signature a certificate that the signer has read the document and verified its accuracy, including citations, quotations, and descriptions of cases, and her pro se status "does not relieve her of this requirement." The court then warned: "Plaintiff is now on notice that the use of hallucinated cases or the filing of documents with related inaccuracies will result in sanctions." No sanction was imposed for the citations in this order.
Why does Adams v. Kiewit Infrastructure West Company matter for law firms using AI?
Judge Humetewa’s order is short and mostly procedural. The motion to amend was struck for failing Local Rule 15.1(a), and the court used the order to remind the self-represented plaintiff, for the third time, of her obligation to follow the rules. The citation problems appear as a related observation: a nonexistent Arizona Court of Appeals decision and a Ninth Circuit citation that leads to an Eleventh Circuit case with a different name.
The court drew the AI inference itself, stating that “[t]hese hallucinations allow the Court to infer that Plaintiff prepared her filing with the use of generative artificial intelligence.” It did not treat that use as the problem. The problem, in the court’s words, was “the failure to confirm the accuracy of the filing,” and the court relied on Rule 11’s signature certification and on District of Arizona authority applying it to pro se litigants.
No sanction was imposed for the citations. Instead, citing an earlier District of Arizona decision that gave a similar warning, the court put the plaintiff “on notice” that filing hallucinated cases or related inaccuracies “will result in sanctions.” Firms documenting compliance may wish to consider that, in this case, the court’s response to hallucinated citations from a pro se litigant was an express warning rather than a penalty.
Implications for your firm
Operational steps a firm reading this case may wish to consider documenting. Strategic and rule-application calls belong to your firm's attorneys.
- Verify reporter citations as well as case names. Here one cite named a case that exists only as a Utah decision at a different reporter cite, and another pointed to an Eleventh Circuit case with a different name.
- Review opposing pro se filings for citation problems; the court here raised them on its own while striking the motion on other grounds.
- Document the notice a court gives. This order's express warning sets the stage for sanctions if the conduct recurs.