"Oglum Bak Git." I think it means "Get away, kid" or something like that. Yes, bak git, bak git, git back ... no ... really.
The victim is a street sweeper who stutters ... so naturally the kids make fun of him. It is thought the street sweeper smacks one of the kids who then gets his older brother (the tough guy) to punish the street sweeper for retaliating. It is then, justice is dispensed.