This industry does not exactly attract the cream of the crop of Human Beings!
I have been on both ends of BDSM porn. No scene should ever continue when someone says "I can't breathe" and if they are crying you ask if they are okay, if they need a min. and if they want to continue Period. They do not have to verbalize a "NO" It is the responsibility of everyone involved to make sure the talent is comfortable.
For those of you supporting this sack of shit I have this to say to you-
You are a pathetic loser if you need to smack a girl around in bed to get off. I hope it helps to compensate for lack of sexual skill or an inadequate penis. 