This probably isn't the first time it's happened. Any woman that stays with a guy that is verbally or physically abusive is playing with fire.
I'm not saying the woman is asking for it, but JFC. The first time he beat the chit out of you, did you think it was a one-time deal? He showed his cards. This is what he does.
And even before he hit you the first time, there were warning signs that it was coming. But you ignored it.
Still, not your fault, but you didn't leave when you saw it coming.