Let me give you some of my personal experiences, Virex.
My uncle had a bottle of soda poured on his head and then was beaten with a frying pan by his wife. He couldn't fight back, because if he did he would've been going to jail. He couldn't call the police either, since they'd just laugh at him.
It took years for him to get custody of the kids, and only after his wife was diagnosed with serious depression. Had the genders been flipped, everything would've been very different.
This last Spring, my Psych 101 class was asked by the sheriff of a nearby county to help them test for sexism in their judicial/police system. A few of us, including myself, volunteered. I figured that it'd be interesting to get an inside view of the legal system, and they were offering a small payment in compensation, so there was that. Anyway, the nine of us that volunteered were matched into five situations, and then one or the other of each pair would call '911' (actually the number used by the 911 workers participating in what they thought was a quarterly testing drill) and we would go from there. The pairs were as follows, sans names and other identifying factors.
Pair 1: A man who pretty much lived at the gym paired with a woman who usually accompanied him to lift weights.
Situation: The man had been beating his 'wife'. The 'wife' made the emergency call.
Result: The man was 'sentenced' to a sentence rated at ~3. (1 being a minor prison sentence, 10 being life in jail)
Pair 2: A fairly average guy paired with a fairly average woman. Neither really exercised or anything.
Situation: The woman had been abusing her 'husband', and he proceeded to call '911'.
Result: After much hemming and hawing, the jury decided in favor of the man, 'sentencing' the woman with a rating of ~2.
Pair 3: A huge guy paired with the smallest of the women.
Situation: The woman had been abusing her 'husband', and he proceeded to call '911'.
Result: No sentence given, citing that the man should have been able to defend himself.
Pair 4: A pair similar to that of Pair #2
Situation: The man had raped the woman, and she called '911'.
Result: Decided in favor of the woman, with a sentence rating of ~4
Pair 5: Me and the woman from Pair #4.
Situation: I had been raped by the woman, and called '911'.
Result: The jury was divided. We were called in personally to add in more evidence, rather than the others which were all anonymous descriptions. We were given some lines to say, but the jury wanted some further evidence yet. I was asked to attempt to bench press 140 pounds, the weight of the woman, as well as a couple other physical tasks. The woman was asked to do some other similar tests. Eventually, after several hours of deliberation, they decided in favor of me, with a sentence rating of ~2.
It wasn't the most scientific endeavor I've ever participated in, but apparently it resulted in a few policy changes in the local courts, after we had revealed that the juries, almost to a person, didn't think that any given woman could reasonably overpower any given man, barring evidence that they could see before their very eyes. (For example, me trying and failing to lift even the solid weight of the 'offender', even without the bar itself trying to stop me, only changed the minds of a couple of them, and it took quite a few more such tests before they were all in agreement.)