Well, let's see. Dad wasn't concerned that he hadn't come come that night, nor was he concerned that the cousin hadn't seen him, so he assumed he'd been arrested. What parent automatically jumps to that conclusion unless that's been a habit. He was running his mouth at Zimmerman with "what's your problem" so that was probably habit. He was probably running his mouth about the drugs at school and he'd had contraband in his backpack in the past. Habits. It takes an involved parent to redirect bad habits. He obviously didn't have such.
I wonder if his obvious embracement of the drug culture changed him from the happy-go-lucky kid to the sullen, easy to lose ones temper gang banger. Perhaps that change of character caused him to take a swing at someone. That may be the “habit’ that started him on the downward skid and ultimately did him in. I am just speculating here.