"You Better Sing The Song Like I Told You To..."

Jared has a thought-provoking post on his reaction to seeing an argument between a man and a woman that had abusive overtones. He writes,
What I saw this morning has been bugging me all day, really, which is why I'm writing about it. Makes me want to go beat the devil outta that guy...and hold the door open for his girl. I know, I know...violence begetting violence, etc. You know what, though? Some people need a beatin'. A guy who'll abuse his spouse is definitely in that category, if you ask me.
I'm with him in principle, but I will think twice before I step into any domestic situation. I know of too many situations where the "hero" winds up catching it from the "damsel." My "little brother," who's a police officer tells me that when he goes to a call for a domestic situation, he lays it out for the woman as soon as he walks in the door: "If you hit me or my partner, you will be wearing these cuffs and you will be going to jail." He has to say that because there's a decent likelihood that she'll try to do something. And it's not even so much about thinking that the woman is being ungrateful, it's a simple matter of personal safety. Fortunately, I didn't grow up in that type of environment, but my grandmother was a hairdresser. I grew up getting all the low-down. For whatever reason, some people are just at home in that type of situation. As strange as it seems to me, there are some people who think that physical abuse is proof of affection. Or something. And I know there are other circumstances that have to do with it, like financial dependency and having grown up in households where abuse is prevalent that confound the situation. It's bad all the way around. What's just as bad but seems worse in some ways is the scene when it's the woman who's beating the man. Mary Mitchell had an article about it a few weeks ago, but apparently I can't link to it any more. But suffice it to say that I feel bad for guys who are in that position. Obviously they're conscientious enough to keep from hitting a woman, but that woman takes his non-physicality as a sign of weakness. Just throwing this out there to see if anybody bites: 1. Would you/ have you ever intervened in a domestic situation involving strangers? 2. Would you be more or less likely to do so if the woman were beating the man? 3. What, in your opinion, should a man do when he is being physically accosted by a woman?