Nah, he's all harsh words (Big Talk) no action. He's just gonna run to his mom for help.
But you never can be 100% sure how non violent someone is, I'll keep what you say in mind if they ever seperate.
Dunno if you mentioned it previously, but is she working? Because if so, that's a perfect place/opportunity for some dude to be her shoulder to cry on. I've been that shoulder before, its easy to get to a female thats in an unhappy relationship.