We, as parents, often forget that not everyone follows our preferred teaching methods. The home-life other kids possess does not always represent the same loving household your son comes home to. We’re so quick to judge another child in their actions and outbursts without giving forethought to their experiences or the struggles they may be challenged with at such a young age. I’m not saying in any form bullying is okay, but even though your child isn’t “that child,” that child isn’t acting out for no reason. I urge you to read this article. It may give you a different perspective:
https://www.washingtonpost.com/news/answer-sheet/wp/2014/11/14/teacher-to-parents-about-that-kid-the-one-who-hits-disrupts-and-influences-your-kid/?utm_term=.3abe1b1d1027