Well... judging from the mud job in the pics, I guess it would have to be expected.
That sort of leads me to wonder if maybe there is an actual violation to using drywall screws in place of machine screws to secure devices in NM boxes.
I know I’ve done it myself before in a pinch, but never really gave it much thought.

You say your man maybe using stainless... he is out of control!
I will sometimes do that do with outside receptacles, but not as an every day thing, since the screws will probably last longer than the receptacles.