Heavy truck and bus tires have a lot of pressure. I wouldn't say he got what he deserved though. He was trying to extort a store owner and when they refused he slashed the tire. IMHO temporary humiliation is not enough, he's probably not given up on the extortion and the store owner is out the expense of the tire.
I've sometimes wondered what I could do in the face of being targeted for extortion by organized crime with the collusion of police. Probably the best approach is to just pay like the other rubes until you can take out the whole gang with a bomb.