3M expert used ChatGPT to draft '0% at fault' defense report
TL;DR
- The Harris County jury assigned 3M 30% liability and awarded $61.5 million, the third plaintiff-favorable verdict across four Watson Grinding trials, with nearly 2,000 additional plaintiffs and a next trial set for October 2026.
- 350 pages of ChatGPT session logs became the primary evidence against the defense's own expert, establishing AI chat histories as discoverable work product in U.S. mass tort proceedings.
- KnightHawk Engineering's formal public response called the coverage a 'selective and negative snapshot' and 'Fake News,' the first on-record denial from a defense engineering firm caught using AI-generated expert testimony.
A Harris County jury awarded $61 million to plaintiffs suing 3M over the January 2020 Watson Grinding explosion in Houston and assigned 30 percent of the fault to the company. The trial record now shows that 3M's own expert witness generated most of his report using ChatGPT.
Court records reviewed by 404 Media show plaintiffs' attorney Will Moye discovered a five-page 'Citation Overlay' during discovery and forced production of roughly 350 pages of ChatGPT prompts from Josh Autenrieth of Knighthawk Engineering, the firm 3M paid roughly $90,000 for its analysis. Autenrieth billed at $475 an hour. Among the prompts he fed the chatbot: 'create an exceptional expert witness report defending the standard of care at 3M' and 'show how 3M is 0% at fault for the explosion at Watson Grinding.' Trial testimony pegged the report at roughly 85 to 90 percent ChatGPT output.
"This expert relied on AI not as an assistive device, but exclusively relied on ChatGPT to form his opinions and write his report," Moye told 404 Media.
Autenrieth defended the work from the stand. He testified that "my opinions were put in there, and AI helped me to draft a straw man to build off of," that he altered any output he disagreed with, and pointed to his "20-plus years of experience in the industry." The explosion killed three people and destroyed roughly 200 homes; the jury assigned the remaining 70 percent of the fault to Watson Grinding.
Moye said the reaction from other litigators has been immediate: "I've got lawyers all over the place saying… 'Holy shit, man. How did you get the prompts?'" Five of the analysts we track had circulated the story within a day, adding it to a running AI-ethics feed that has logged more than a hundred entries in the last three months. Knighthawk Engineering, Autenrieth, and 3M did not respond to 404 Media's requests for comment.
What others are reporting
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Futurism Read →
Frames the case as a discovery precedent for the broader legal profession, raising whether AI-assisted work product across the sector is now routinely subpoenable.
This expert relied on AI not as an assistive device, but exclusively relied on ChatGPT to form his opinions and write his report.
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National Law Review Read →
Provides the specific 30% fault apportionment, confirms this is the third plaintiff verdict across four trials, and notes nearly 2,000 additional plaintiffs with the next trial in October 2026.
The 3M Supervisor admitted for the first time at trial that he had express knowledge the gas detection system was non-functional.
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ABC13 Houston Read →
Local Houston coverage tracking cumulative verdict totals and plaintiff attorney commentary on the litigation's ongoing trajectory, published August 12 ahead of the ChatGPT story breaking.
It tells 3M this case is going to continue to go on.
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Blaze Media Read →
Includes KnightHawk Engineering's formal on-record denial calling coverage 'Fake News,' and documents that the expert billed $82,650 for 174 hours of work that was primarily AI output.
He acknowledged the prompts he put in were biased toward 3M to help 3M win the case, and it's really egregious.
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Gadget Review Read →
Surfaces a Canadian precedent rejecting AI-generated expert testimony outright and frames the 350 pages of chat logs as an inadvertent AI witness against the party it was engaged to defend.
They hired him and he used ChatGPT to write these reports, so really, ChatGPT was the expert in the case.
Shared on Bluesky by 9 AI experts (top 5 by trust)
Originally reported by 404media.co
Read the original article →Original headline: 404 Media: 3M's Expert Witness Used ChatGPT for '85–90%' of Report in $61M Fatal Explosion Case