Of course not. It's perfectly possible that the drunk girl would have negotiated the two-lane road back to North Andover without doing a head-on and killing herself and who knows how many others. I'll bet Henri Paul could have, although we'll never get to find out, since Monsieur Paul is no longer coming down for breakfast.
If she’s constantly making herself available as a free ride for her friends to drink then she is enabling them, because they know they can use her as an escape route every time.
She was merely trying to mitigate a bad situation she had no role in causing.
If she said no then the other kid would have had more difficulty getting out of her jam and would have thought twice about getting herself into that situation the next time.
Yeah, there's a public policy. Punish the drunks by making them drive themselves home! With luck, they'll be alone or with fellow drunks and only hit a tree or a support column.
As I said, she should’ve called her friends’ parents or reported the party to police and let the proper authority figures take care of the kids. She helps to keep it secret from the people who deserve to know about it by acting as the getaway driver.
Meanwhile, the logic “most of us did it as kids so we shouldn’t say it’s bad now” is the kind of thinking that’s led to the continuing liberal decay in our country’s ethical values and lowering of moral standards from one generation to the next.