Sounds like he has found a way to cope. You just need to give him a way to cope IN class.
He may escalate, though.
When I was his age, I just walked out of school and went home and called my mom.
She then called the school asking them to have me ready because I had an appointment. She then showed up at the school.
That caused a lot of wailing and gnashing of teeth.
Things changed - I got to go to the library two hours out of the day and sat in back doing my own thing - reading. I just had to take the tests with the rest of the class.
