More relevant than this absurd unenforceable "contract," is what he actually did to her in carrying out its "terms." In the gay community, some guys are into bondage, and sometimes even insist upon it. Odd, but that is the way it is. But yeah, just on the existence of the "contract" alone, I would fire his ass myself.
BDSM contracts like this aren't meant to be legally binding. Their purpose is part symbolic and part setting expectations that both parties consent to. The issue here is the woman was obviously coerced and it wasn't consensual.
The woman probably signed the "contract" agreeing to (almost certainly wanting to) do those things but at some point he crossed the line or she changed her mind in which case the "contract" is meaningless and he coerced her. Which makes him scum obviously.
From the article, it looks like the breaking point was when he asked her to sleep with other men in front of him.
This guy is such a loser that he tried but failed to become a cuck.