For a little while it seems like Monty might be the one to turn on his former BFF and take him out for good. In a flashback, it's revealed that Bryce threatened Monty to leave Tyler alone in the locker room the night of the Homecoming game. He told Monty that if he didn't stop bullying Tyler, Bryce would go to the police with information about everything Monty had done last year, including Tyler's brutal assault. That right there was enough motive.
Monty proceeds to repeatedly try to "break Walker in half" during the Homecoming game, and confronts Bryce by the Hillcrest bus after it's over. "I will take you out," he declares, before Bryce snidely replies, "No you won't. You're just a coward, you always have been." In the end Monty isn't the one to kill Bryce, even though that's the tale Ani spins for the sheriff. His own fate is just as bleak, though — he's killed in jail.