Seems these people are forgetting this was in a, presumably crowded, food court, and not a dark alley. Shooter is on very thin legal ice, very thin.
Also, seems some of these folks don’t have experience with the garden variety bully. This wasn’t some madman running up on the shooter, this was a bigger guy clearly trying to get a reaction.
If the aggressor had spoken any “fighting words”, and yes that’s a legal term, I might well have shot him. That does not seem to have been the case.