Z, I don't think it's an anti DB attitude, DBing isn't about takinh abuse and in the case of abuse I think we would all agree to protect yourself first!
I think having the roommate there is a good plan if you are afraid for your safety at all. It will hold him accountable for what he does as well.
If you decide you don't want to D I think you need to set a strong boundary like V said. And I know you can't force anyone to do anything but it does sound like an anger management course would be helpful!
Good luck in talking to him. Will you be able to speak later or will you have to wait for another night? What do you plan to do since he was out?
Me 28 / H 28 M 1 / T 2.5 BOMB 12-3-14 "I don't feel like myself any more" Still living together, separate rooms.