When Expert AI Prompts Become Discoverable
A May 18, 2026 D. Conn. discovery order in Conservation Law Foundation v. Shell, as reported by Mayer Brown, suggests that expert AI prompts and instructions can be treated as discoverable methodology material under Rule 26.
Most litigators now assume opponents will ask whether AI was used in expert analysis. The harder question is scope: if an expert used a model, can the other side demand the prompts and instructions used to generate the output? A May 18, 2026 order in the District of Connecticut indicates the answer may be yes when those inputs are part of how the expert reached conclusions.
What Mayer Brown Reports the Order Did
Mayer Brown's June 10, 2026 litigation update reports that Magistrate Judge Thomas O. Farrish, on May 18, 2026, ordered disclosure of AI prompts used by an expert in Conservation Law Foundation, Inc. v. Shell Oil Company, et al. (Case No. 3:21-cv-00933, D. Conn.). The same update identifies the order as ECF No. 970 and notes that the ruling was stayed pending review under Rule 72(a).
Paraphrase + inference (from this reported ruling only): when prompt engineering is part of an expert's analytical process, a court may characterize those prompts as discoverable methodology rather than protected mental impressions, at least absent a successful objection.
Why Rule 26 Framing Matters
Rule 26 discovery disputes often turn on whether requested materials are tied to the basis of an expert opinion. If AI prompts define assumptions, constraints, or analytical pathways, an opposing party can frame them as inputs needed to test reliability, replication, and bias. That framing is not limited to model outputs; it reaches process artifacts that shape the outputs.
For expert teams, this raises immediate workflow consequences: preserving prompt history, separating attorney strategy from expert methodology where appropriate, and documenting what was actually relied upon in final opinions.
The Stay Is Not the End of the Story
The reported stay pending Rule 72(a) objection means this issue remains live. This is one district-court discovery ruling, not a universal federal rule, but it is a warning signal that parties are already litigating prompt discoverability and that at least one court has treated prompt logs as potentially in-scope methodology material.
Litigators using AI-assisted experts should pre-plan for this challenge in expert protocol design, discovery negotiation, and motion practice. Waiting until a compel motion lands is usually too late to reconstruct clean records.
This content is legal information, not legal advice. It does not create an attorney-client relationship and cannot substitute for consultation with a licensed attorney about your specific circumstances.
References & Sources
- Mayer Brown, Court Orders Disclosure of Expert Witness's AI Prompts: What Litigators Need to Know (June 10, 2026). Reporting that Magistrate Judge Thomas O. Farrish ordered production on May 18, 2026 (ECF No. 970) in Conservation Law Foundation, Inc. v. Shell Oil Company, et al. (Case No. 3:21-cv-00933, D. Conn.), with a stay pending Rule 72(a) objection. Source: mayerbrown.com.
- Federal Rule of Civil Procedure 26 — scope of discovery and expert discovery framework used to litigate methodology-related production requests. Source: law.cornell.edu/rules/frcp/rule_26.
- Federal Rule of Civil Procedure 72(a) — objections to magistrate judge non-dispositive orders, including district-judge review and modification standards. Source: law.cornell.edu/rules/frcp/rule_72.