The parents probably chuckled heartily, slapped him on the back and said, "good work son, you're a man now - everyone goes through this phase and no-one got hurt, so don't listen to anything that stupid judge is going to tell you about 'maturity' and 'remorse'."
Well, probably not exactly like that, but it wouldn't surprise me. There are an awful lot of parents who don't care these days... I remember an incident in my own country a couple of years ago, when a drunk teenager crashed his car - again - and put his girlfriend in hospital. He announced that he intended to drink and drive again, and his mother supported him because he's a 'good boy' and just needs to learn more about drinking.