While what he did was stupid IMHO, we have to remember it is his car and we didnt buy it for him. Unfortunately for his car, he can abuse it however he sees fit. Im just glad to see he and the car is ok. Like others have already pointed out, it could have been much much worse.
The only thing that really pisses me off, is that we pay for the outcome that luckily didnt happen in this situation, but does in other situations through higher insurance premiums.