alt Hacker NewsI agree, but it's not like Anthropic was running to tell the lawyers and the judge in this story. The most likely scenario is your friend would just let slip he's using AI, or people who know him would let it slip, and the lawyers or judge will demand the conversations for discovery.
If I was strongly motivated to gather AI analysis of litigation, I think that I would turn to Tor if possible, and remove any specifics from the discussion.