Well I have deliberately inflicted pain in the dojo but excessive - well I didn't think so.
Damage - well there was some bruising. I wouldn't call that excessive either.
The question is loaded - it said hurt not damage. Excessive according to whose definition.
Pain is part of what we do. Kime is not necessary for a technique to work, even the pins, but the potential is there as is the need to be aware of the possibilites. Not to mention a certain amount of toughening up.