We had a jerk parent parked next to us at Malvern last year. Little kid was on a mini 4 wheeler. My Dad finally said something to the guy, and he was not too pleased. Told my dad to mind his own business, he knew what motivated his kid. But the guy was really just an ass that I am sure had never ridden a motocross track.
Matthew started racing at 4. Was never the kid to beat on 50s or 65s.......and I did not care. I have let him take things at his own speed, and we did not ride like every weekend either. Now on the 85, things are clicking better, and in his last 8 motos, has had 5 moto wins. Kids will do things when they are ready, and no need to push them into riding over their head. They will just get hurt or hate the sport.
As for this jack ass.....CRA should send him a letter banning him for at least a year period. OMA and SW Ohio MX, should both send him a letter stating they heard about the incident, and warn him now. It will not be tolerated and if there is any incident it will be dealt with immediately and harshly.