I'm not interested in "If" statements. The fact of the matter is that he was just a harmless bloke walking home from work, and they chose to attack him. He was not obstructing them in any way at all.
It's always been my understanding that the police are not permitted to brutalise members of the public without legitimate cause. Did this change and nobody told me?
But they weren't forming a line on that corner. They were just walking in a straggled line. They didn't even form a police line when they stopped to admire their handiwork.
One guy who was clearly not taking part in the riot? One guy who was walking in the opposite direction? They could easily have stopped and asked the guy about his intentions; they could even have detained him if they'd had genuine concerns. But they didn't bother. Perhaps it didn't enter their tiny little brains.
I can't believe that you're even trying to justify the attack. It's just bizarre. Do you come from a 3rd world nation where this sort of thing is normal, perhaps?