Mama mia!
I would, as a parent, known what the little jerk was doing. 14 year olds are not that swift. I would have stopped him from taking it to school.
As for the teacher, she blew it. She should have taken the damn toy away from him.
So, two safety nets failed before all hell broke loose.
Everyone should be rethinking how they personally can do better next time. *If* they want to do it better.