If I drank one 16 0unce 5.5%alc beer, will I pass an EtG test in 34 hours?

Nothing like being on probation and trying to beat the system. Probably not pass.

You could fail, not enough facts to make a prediction, but I have seen it happen. And I have seen people pass in less time. Anything can happen when you roll the dice. Sorry I can't make your friend feel better about taking a penitentiary chance for a beer, but he may as well hold his head up and hope for the best but plan for the worst.

That's just reality.