Are you going to get close enough to apply first aid to your assailant? Are you going to give them a second chance to do you harm?
I have thought about this very situation and cannot say for certain what I would do. Obviously it would depend on the specifics of the actual event and if it was even safe to render aid, but even then just not sure. I would like to think that I am the type of person that would assist if it were safe, but it would be a difficult decision.