From chapter 19:

Dr. Jurgen, the professor, was distributing test results. “Hallson,” she said.
A young man walked forward and crossed paths with another male student. Hallson shoved his shoulder into the other man. The student reacted immediately and slammed a fist against Hallson’s chest.
Michael looked up at the sound of the first blow. The diminutive teacher backed against the wall from the sudden confrontation. Michael jumped out of his front-row desk, spreading his arms, and pushed his small body between the two students, who were yelling and threatening more punches.
Every student stared, unmoving.
“OK. Stop, stop!” the professor yelled. “That’s enough with the demonstration. Thank you.”
The formerly-fighting students smiled, shook hands, and returned to their desks.
Michael dropped his arms, and stared open-mouthed at the smiling professor.
“Sorry for the little act. That was my way of introducing the next section in our Psychology class on altruism,” Jurgen announced. “And only one person jumped in to break up the fight, the smallest student in the class, Michael Shale.”
The whole class stared, stunned at the theatrics.

When I presented this chapter to my local writing group for critique, one of the members wrote “This isn’t believable.”
I guess truth is stranger than fiction, because this is what really happened in my Psychology class in college. And I was the guy that jumped up between the two fake fighters. So there!