This goes both ways. When I (a man) was the target of some really pretty severe domestic violence (I was threatened with a knife, attacked with blunt objects and more several times a week), the reason why I eventually decided (quite deliberatively) to respond with physical force was that I looked at what my options were in the legal system and realized I didn't have any, that if I called the cops, they'd probably arrest me, not her. So I hit back with very measured force (except one time she hit me from behind with a blunt object and I hit back with full force once out of fear she might have knife in her other hand). Given the scale of what I was going through I don't think anyone would claim it wasn't self-defence.
So these things to some extent perpetuate eachother.
Whether or not that is the case, it is also possible that it is more that when they are (or, in the case of murder, expect to be) the victims of such things, they feel they don't have other effective remedies outside the legal system, whereas men feel more able to respond effectively (whether or not legally) with physical violence.