I'm going to start shooting because someone got pushed down and had their backpack stolen?
I'm going to start waving my gun in the air because someone got punched in the mouth and had their iPad lifted?
I wouldn't be shooting because they hit me in the mouth. I would be shooting because multiple attackers are starting an attack on me which in my mind CLEARLY constitutes a eminent risk of death or grave bodily injury.
I wouldn't shoot if my powers of knowing the outcome in advance were working. Since a fat lip isn't worth a life.