Your expert used AI. What to ask before you serve the report

Yes, your expert can use AI, but you have to ask before the report is served, in writing, and you have to get a true answer. The reason is simple. When an expert's report carries fabricated citations, the court excludes the expert, and the client pays for it. On August 18, 2026, a federal court in Washington excluded an expert report over hallucinated citations. With the expert gone, the plaintiff had no evidence left, and the case was dismissed with prejudice.

What happened in LeDouxx

The case is LeDouxx v. Outliers, Inc., 2026 WL 2408808 (W.D. Wash. Aug. 18, 2026), unpublished. I could not find the order on a public docket, so the facts below come from the Washington State Bar's summary and you should pull the order from Westlaw before you cite it.

The expert's report cited academic articles that did not exist. The plaintiff's lawyer conceded she had a role in preparing the expert reports, and that the bad citations came from two AI tools she said she did not understand how to use. The court excluded the report under Federal Rule of Evidence 702. It also noted that the same lawyer had already been sanctioned on July 24 for dozens of inaccurate citations across at least five of her own filings, and a January 2026 order had excluded other experts whose reports also carried hallucinated citations.

Two different penalties, and only one is recoverable. A sanction on the lawyer is a fine and a bad week. An excluded expert on a case that needs one is the end of it.

The rule that puts the burden on you

The standard everyone now cites comes from Kohls v. Ellison, No. 24-CV-3754 (D. Minn. Jan. 10, 2025). A Stanford professor filed a declaration that cited two nonexistent academic articles and got the authors of a third wrong. The court held that this "shatters his credibility with this Court."

The passage that matters for you is about counsel. Rule 11 imposes a "personal, nondelegable responsibility" to validate what gets filed, and an inquiry reasonable under the circumstances "may now require attorneys to ask their witnesses whether they have used AI in drafting their declarations and what they have done to verify any AI-generated content." That is one district judge, not a rule. But LeDouxx shows a second court reaching the same result, nineteen months later, with a worse outcome for the client.

Rule 26 makes the question awkward

Under Rule 26(a)(2)(B), a retained expert's report must state the opinions and their basis, list the facts or data the expert considered, and be "prepared and signed by the witness." Rule 26(b)(4)(C) protects communications between you and the expert, except for compensation, facts or data you supplied, and assumptions you supplied.

My reading, and it is only my reading: asking "did you use AI, and how did you check it" is a protected communication. The answer about what the expert actually relied on is not, once it becomes part of the facts or data considered. So the question is safe to ask. What you should not do is what the LeDouxx lawyer did, which is help prepare the report with tools you do not understand. The rule says the witness prepares it, and a judge reading a lawyer's admission that she had a role in drafting it will not be sympathetic.

What to do before the next report goes out

• Put an AI clause in the engagement letter. The expert states whether any AI tool touched the analysis or the drafting, names it, and agrees not to upload case materials to a consumer product. The prompt discoverability rules are one more reason the last part matters.
• Cite-check the expert's sources, not only the cases. Your habits are built around fake case law, but the fabrications in both Kohls and LeDouxx were academic articles. Pull every one and confirm the authors, the journal and the finding.
• Require the expert to certify, on the signature page, that he or she personally read every source cited. A signature under penalty of perjury is not a formality, as the Kohls court put it, and a certification makes that concrete.
• Repeat all of it for rebuttal and supplemental reports, which get written fastest and checked least.
• Run the same source check on the other side's expert. A fabricated reference in an opposing report is a Rule 702 motion waiting to be written.

If you have already been through a citation failure of your own, the discipline record in our piece on 2026 sanctions shows how the second document, the one written after you discover the problem, decides the penalty. The general sanctions picture is in the hallucination sanctions guide.

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For the wider firm policy this clause belongs in, start with the free guide, and see our AI tool picks for products worth putting in front of an expert.