What in the world is wrong with him?

My husband and I have a 16 year old son is an overall good kid and he follows most directions given to him. Because of this, we weren't very hesitant to get him a car when he asked for one. He has had it for maybe 5 months now and hadn't had any tickets or anything like that (which we expected him to have at least 1 by now). But, today he came home and told us he had gotten his first speeding ticket. We knew it was only a matter of time so we asked what it was for. "I went past a stopped school bus. I didn't see the sign." WHAT THE HECK! The sign is bright red, says stop im big white letters, and it flashes!! How could you miss that??? I asked him how much it was for and he said "$800- I kinda went past 2 busses." Then I was really pissed! I absoultely cannot believe how careless he was being and he continues to brush it off like it's nothing. He could have hit someone's child. And he doesn't seem to car, understand, or think it's a big deal.