You take a clockmaker who's used to working with hand-operated lathes, mills etc. and let him work for a few years using CNC versions. For sure he'll probably be worse at using the traditional machines when he comes back to them, but that doesn't mean he's any dumber or worse at making clocks. He's just out of practice, same as if he'd have spent a few years staffing a convenience store or anything else.

That seems to be precisely what your study shows as well, though I only read the summary. Say the AI lowered the endoscopists' workload by (for illustration) 20%, so they got 20% less practice per unit of time, which made them have a performance that was 20% worse in the trial. I would expect the same to happen if they got assigned to do paperwork for 20% of their time as well.

I'm not trying to be argumentative, perhaps we're in agreement here, I'm just clarifying my point.

There's a famous talk about the importance of knowing when to use which level of automation, and maintaining currency at all levels you expect to need to use: https://youtube.com/watch?v=5ESJH1NLMLs