This is actually been our worst time in school. My Aspie desparately wanted to fit in and make friends this year and was in regular classroom but, the atmosphere in Middle School is totally unforgiving when you are quirky, nerdy or ackward. Our kids are taunted, teased and picked on to no end and eventually can snap. Mine did and we've had a long hall trying to recover from 1 mistake. Please consider the stress of middle school, let alone the curriculum! If he needs a break, I'd definitely consider it or find an aide, resource provider or teacher whom he can confide in and find reprieve. This was just a compounded, frustrated outburst, Aspies don't like failure, if anything they want to fit in, be perfect at what they do. Keep working on deescalating and open communication, not to add to the problems of a teen having a disability that's having trouble controlling himself in a hastile atmosphere. Easy to say when you're not in the midst of it all.
Best Wishes!