This officer unfairly tries to keep Shaka from using the bathroom when he really has to go. Shaka scoots past him, and the guy dishonestly accuses him of an assault on staff. (It doesn't help matters that the officer, a white dude, seems to feel like being white makes him superior.)
The guy just keeps bullying Shaka, and finally Shaka actually does assault the guy. By the end, the guard is unconscious. Shaka is sent to solitary confinement for four and a half years due to this.