I wanted to break a argument over violence in general. What happened in the thread OP is not excusable in my opinion unless it was know that the guy doing the aggression could kill with his bare hands, but that's probably not the case.
What normal people ignore in heated gunfights and other actual combat situations is that the participators are under adrenaline. I argue people getting into a fight get gradually less restrictions on what they can do the more intense it is. A fistfight is not much, but if a person starts a gunfight, he should know that the person being attacked is not being held back by the NAP until the fight has since long passed. If you try to flee, for all the enemy knows, you could be trying to put in range before trying to shoot again.
Again, not arguing for the video in the OP, just wanted to throw this out there.