The bartender does that only until he gets busted by a police sting operation.
A good friend of mine had his nascent teaching career destroyed when he some confident-looking 20 year old chick dropped a 6 pack of Bud Light on the counter of the store he managed part-time. He didn't bother asking for ID (which he was typically pretty strict about) and was led out in cuffs.
He received a conditional dismissal after 3 years of probation, but explaining a 3+ year career gap ("So, why did you quit teaching after 6 months to fix cars?") takes you off the fast track.