the kid snuck out of the house and purchased a video game that he wasn't allowed to buy.... the father punished him...
i don't see any wrong doing on the fathers part (except the hiding the key better)
the kid was lashing out.. but he obviously wasn't thinking of the consequences... he is 17 ... should know better by that age, unless you have some sort of personality disorder... antisocial or similar.
I think the medical term for what this kid has is called "off his fucking rocker."