If ChatGPT did something wrong, that lawyer would still be on the hook for deciding to continue using this tool so responsibility/liability/authenticity is not a problem.
I get that they want to make some kind of subscription service to replace lawyers with AI (a terribly dystopian idea in my opinion, as only the rich would then have access to actual lawyers) but just like Tesla needs someone in the drivers seat to overrule the occasional phantom breaking and swerving, you need an actual lawyer for your proof of concept cases if you're going to go AI in a new area.
You'd also need a fast typist to feed the record into ChatGPT of course, because you can't just record lawsuits, but anyone with a steno keyboard should be able to keep up with a court room.