I recently reviewed a MR from a coworker. There was a test that was clearly written by AI, except I guess however he prompted it, it gave some rather poor variable names like "thing1", "thing2", etc. in test cases. Basically, these were multiple permutations of data that all needed to be represented in the result set. So I asked for them to be named distinctively, maybe by what makes them special.
It's clear he just took that feedback and asked the AI to make the change, and it came up with a change that gave them all very long, very unique names, that just listed all the unique properties in the test case. But to the extent that they sort of became noise.
It's clear writing the PR was very fast for that developer, I'm sure they felt they were X times faster than writing it themselves. But this isn't a good outcome for the tool either. And I'm sure if they'd reviewed it to the extent I did, a lot of that gained time would have dissipated.