My post came up after yours, Wyldfire. If had seen your post beforehand, I would have added more about handling crazies, hence the addition of the disclaimer.
But, following in the "fight or flight" logic... If it becomes obvious that the scene can't be cooled, that's when one would take their leave.
If anyone has read "How to win friends and influence people", there is one "rule" that says: Never confront someone when you are angry.
Too much emotion prevents productive interaction. By leaving, not only do you avoid fanning the flames, but you create an opportunity for the emotion to dissapate and logic to take hold again. Upon your return, you can resume the confrontation in a more civil tone. Until it escalates, at which point you leave again... lather, rinse, repeat.
To me it seems like common sense, but obviously some people are just sheep waiting to be sheared. I mean, do you stand there staring at a bee's hive swarming with angry bees? Sure, there's honey in there, but how many bees are there to sting you? People who get abused, in my mind anyway, see the bees and go for the honey anyway. And this is my point. If someone is too lazy to find another "bee's nest" (one with the potential to have "fewer bees"), doesn't have a healthy self respect (like's to be stung/****), or doesn't have the self esteem/confidence to believe they can actually find a better bee hive or can do without the honey, then those people are walking pin-cushions for bee's stingers.
I know this seems like I'm anti-victim. It should, I AM. I am anti-violence/abuse... but it takes two to tango. There is no abuse if there is no victim. It's like driving a car: The best way to avoid a traffic accident is to not be around when it happens (abstinence/aversion). The best way is not "drive a safer car" (survival). That would mean you plan on getting in an accident, right?
So, in these abusive situations, someone had to stick around and become a victim. Someone knew the accident was coming and must've thought they were "driving a safer car", or thought they had the capacity to fix the problem, or, were oblivious to the impending danger.
Now don't flame me - I'm not suggesting that abusers are right or just. I'm pointing out that a portion of the blame should be on the victim.