Environmental litigation in Connecticut has revealed yet another AI-related banana peel for lawyers to slip on. Namely, the discoverability of prompts provided to artificial intelligence software by the opposing party’s expert witness.
Earlier this summer, a federal district court in Connecticut ruled that an expert witness’s AI prompts were within the scope of discovery under Rule 26(b) of the Federal Rules of Civil Procedure. The AI software and the expert witness’s prompts, the court said, were part of the expert’s methodology and were, for that reason, “fair ground for discovery.” See Conservation Law Foundation Inc. v. Shell Oil Co., No. 3:21-cv-00933 (D. Conn., May 18, 2026). With this view of the law in mind, the court ordered the Conservation Law Foundation to supplement earlier responses to interrogatories and document production requests by providing “any artificial intelligence prompts and/or queries used by [the expert] or her team in the course of producing her expert witness report.”
However the court eventually rules, expert witnesses who use chatbots must assume that someone will ask what they typed.
The court also raised the specter of sanctions against CLF. “If, after a diligent search, CLF determines that no additional responsive materials exist, it shall say so in its response, signed by the appropriate person under Rule 33 or 34,” the court wrote. “Rule 37(b) sanctions may then become available to the defendants if that representation is later revealed to be untrue.”
The ruling appears to be the first federal court decision to address the discoverability of an expert’s inputs to an artificial intelligence tool. However, the May 18 discovery order is likely not the court’s last word on this topic. The Conservation Law Foundation immediately filed a motion to stay the discovery order, which the court granted on June 3. A definitive answer may be forthcoming in the fall.
The case has been vigorously litigated in the five years since it was filed, with nearly 1,000 docket entries so far.
The Conservation Law Foundation presented three arguments in opposition to the court’s discovery order. First, it argued that an expert’s AI prompts are not discoverable as “facts or data considered” under Rule 26. Second, CLF contended that a Rule 29 stipulation that the parties would not seek each other‘s “expert notes, drafts, or communications needed by, and made during, the report drafting process” shielded the prompts. The court rejected both arguments.
Finally, CLF argued that its expert had only provided search terms to the AI tool — not “prompts.” The court declined to accept this characterization of the evidence, noting that another of CLF’s experts had referred to the same AI inputs as “prompt[s]” in a sworn filing. CLF asserted that it had already provided to the opposing party all of its expert’s search terms and that it had no further information — whether characterized as “search terms” or “prompts” — to provide.
Shell Oil argues that, without the prompts, it cannot test whether the AI tool used by CLF’s expert witness excluded responsive materials, introduced bias, or hallucinated.
Food for Thought
The Conservation Law Foundation v. Shell Oil dispute should matter to any litigator who takes or defends expert depositions. It should also matter to anyone advising an expert witness who plans to use a chatbot on case materials.
However the court eventually rules, expert witnesses who use chatbots must assume that someone will ask what they typed. Litigators will be asking pointed questions about which AI tools the expert used and whether prompts and search terms have been preserved for discovery. The court’s ruling also suggests that Rule 29 stipulations in the future should be drafted with artificial intelligence tools and AI prompts in mind.
Litigators who want a broader view of how late-surfacing documents reshape deposition practice may also find useful background information in our recent article on tardy document production and reopened depositions.
When one of your cases is in need of a construction expert, estimates, insurance appraisal or umpire services in defect or insurance disputes – please call Advise & Consult, Inc. at 801.641.8304, or email experts@adviseandconsult.net.