Massacre, I think you hit the mark.

I think a gun would've made an impression, these were kiddie punks and not real gang bangers, or he'd have done serious hospital time at the least. He was lucky to walk away. My first guess would've been disengagement, he certainly had plenty of opportunity before he provoked the attack.

I suspect one of the punks will get pinched and roll on his pals, and they'll all end up being the children of concerned parents and get handed community service and reparations and a mark on their record for 4 or 5 years. I also suspect the fool will sue his employer and retire comfortably on an undisclosed settlement.