(((hugs))) When one of my ds was around 5, he punched the camp bus counselor in the face, because "she wouldn't shut up". Now we know he has a language disorder and obviously people getting in his face and screaming is a hair trigger for him. We had to go over that it's not ever acceptable to ever punch someone in the face, even is someone else crossed into his personal space.
Aggression, face planting and shutting down were DS coping skills. Age and finding other ways for DS to cope seemed to redirect his outbursts, but it is tough.