OP did something ethical, but she should have just called the cops in front of him so he knew they would arrest him. Calling after he leaves would be seen as underhanded.

I'm not justifying what is happening to OP, but explaining how it is seen by the people angry with her.

There are a million things you can do to stop a friend driving drunk and I've done many of them in my time. Waiting until they leave to call the cops is just a dick move.

We obviously can't say what she did was bad, as it was reporting someone for being a drunken fucking idiot, who could kill people, but the way she did it was really fucked up.

Loosing his licence, his job, is all on him. He fucked up, but instead of any of numerous options open to OP, she picked the one where she waited until he went, then drunkenly called the cops in front of another friend who probably thought it was hilarious at the time.

But she is only nursing a hangover, the friend is facing court, getting a new job without a licence and a pretty fucked up and uncertain future for at least the short term. If he was a mate I'd call him a stupid dickhead and then try and help him pick up the pieces.

The bloke is 26 and anyone who drinks that much and drives, usually does it more than once and probably frequently, so it's good he was caught, maybe it's the wakeup call he needs. But OP fucked up and let someone else know she did it, so has to face the consequences of being seen as the reason he was caught.

Yes, he did it to himself, but OP gave everyone someone else to share blame for it. He'll need support as he lost his job, faces thousands of dollars in legal costs, possible jail time, probation and driving restrictions.

For right or wrong, her call cost him an astronomical amount of money, uncertainty and legal problems. She's not at fault, but she knowingly caused it to happen, knowing full well the possible outcome.