I am with the others on this, you say she is overreacting, I believe you're oversimplifying and minimizing a potentially dangerous situation. It wasn't just a 'communication' with her nor was it a minor injury. Clearly, you could be right that it's not a regular thing but that's highly unlikely. He hit her and didn't even want to admit it, one bad sign, saying he knew he was wrong and tried to cover it up with denial. Second, he hit her hard enough to cause her to burst out crying... obviously thats a major blow. This is a serious problem.

I like what Anika said and who in response to High Treason's answer, which begs to question "HT, do you hit your mate?" I mean do you feel it would be ok to do that to express that you were angry at them? Really.

Shauna, never give into the idea that you're trapped. Even lacking a network of your own friends nearby you can find a shelter, taht's what they are for. Please, call one of the shelters nearby and go there. This will do a couple of things. Not only get you out of the dangerous situation but at the same time communicate to him that you won't put up with it. If he truly cares and is remorseful, he'll get help. I wouldn't return until he does.

That's my take. Hope this helps.
~S4