Thing is, that man had the option of leaving, the poor mother was stuck.
Too bad the Mom didn't have a black belt.
I don’t see why he could leave but she couldn’t. Obviously she couldn’t leave the kid, it’s her kid, but she could have left the area with the kid just as easily as he could. And since the source of the disturbance was her kid really she should have been the one out. Obviously he shouldn’t have hit the kid, or even her, but the idea that if somebody’s kid is giving you a headache with their antics in a public place you should leave is just plain silly.