I'd be amazed if anyone who responded yes steps up with an explanation. It's like the old, "do you still beat your wife?" question.
During 20 years with my Sensei, I saw him "intentionally inflict serious injury" during class a time or two and I thought then and I do now that it was a perfectly logical response to a real threat. We're not talking about a sadist who hurts students for the pleasure/fun of it but an instructor dealing with a determined, trained martial artist.
My sensei has passed away so pressing charges for assault is not an issue. Of course, he was in his late 70s when all this took place and few bullies want to complain that a little old man beat them up.