WeepingAngels said:
It is normal to allow people to attack you and once they back off you shouldn't take it any further, outside of the police who would respond with violence if the attacker assaulted them.
Assuming the police aren't acting in self-defense, where has anyone said they would condone an unneeded level of violence after the assailant has backed off from the police? Sure, arresting them is reasonable, but that's because the officer, unlike the guy here, is actually authorized to carry out the law and arrest the person.
Also, we're making a distinction between self-defense and counter-assault, for lack of a better term. If the woman was still attacking the man, then he would have had every right to retaliate with violence in order to protect himself. The thing is, by the time he attacked her, she was no longer a threat to him and he was no longer in any need of defending himself. His assault was an unnecessary act of violence on his part, as it was hardly committed in attempt to protect himself or others.
Finally, some people simply don't thinking assault someone in an act of revenge is justifiable. Heck, many major religions even forbid it, and the law in many nations does too. The best thing to do is to actually get someone who is allowed to arrest the person. Doing anything else is many times illegal and will get you into trouble, and it also adds an unnecessary amount of violence to the situation, which already has too much unnecessary violence associated with it to begin with.
If the attacker is drunk or messed up on drugs, they are too be treated more gently, don't know if this rule applies to the police though.
This has nothing to do with drugs and/or drunkenness. Once again, if she was still attacking him, there would be no question that his retaliation would be justifiable self-defense, regardless of her state of mind.
Really, her state of mind is just a distraction in this case. At best, it serves as speculation for why she committed such a bizarre act of assault. However, in determining whether or the man's act of violence was justified, it is completely irrelevant.
Edit: Sorry for the double post, but I didn't see your response before starting to type out my previous one.