Yep - and since the vast majority of set restarts happen on tackles 0 and 1 the completion stats are massively inflated for the whole league.
Sharks completed 75% against the Eels (28/37) but they received 2 set restarts and 8 penalties. Their actual completions were 18/27 - which is 66% - and that doesn’t take in to account any regular “six more” calls (pass knocked down, attempted strip, etc.).
The other thing is that if you run it on the last tackle and get caught and hand it over - that’s a completed set. If you run it on the last, get caught and throw a wild pass knowing it is the last - which is dropped - that is an incomplete set.
I think a competed set should be “you get the ball, and you either score, force a dropout, force a mistake, kick the ball after tackle 0, or attempt to run the ball on the last tackle”. There is no stat for that.