The child was Hardheaded but did not deserve all the thrashing. What he should have done was lifted the desk and took her out of the room. What would she do? She would surely get of the desk then. That would be a more non violent way to deescalate the situation. She would have been outsmarted, out of the class, and pissed.
I'm sure all you guys grew up with hardheaded class mates who couldn't follow directions at all costs. When you became an adult, you realized these kids had most likely, horrible upbringings.