This is one of those situations where all parties are idiots. The school is full of BLEEP for their participation-trophy policy but the dad is out of control (my opinion).
The dad is showing his son how proud he is of him. He is not running off with the milk money to shoot smack with the babysitter. "out of control"? He is prideful at worst but, I would be too if my kid worked that hard. (my opinion).