[RWebb]

actually, sammy is not too far from the truth in MOST - maybe all - states

once you have defended yourself (guy on the ground, curled in a ball, disabled -- maybe not too far from the scene described) then you need to back off (legally)

there may also be a higher standard for a trained person like a black belt (of course, the Chinese might not recognize a lower level black belt as highly trained...)

So if you wipe somebody out - stop. If you continue to attack when there is no longer any danger then you might get prosecuted.

But, here, she was a very small boded person, female, under threat of a heinous crime. Few cops would do anything (except maybe offer her a billy club); if they did, then she would surely not be prosecuted; if she was, it is hard to imagine a jury that would convict.