I agree you have to choose your battles. But you also have to choose the situations you put yourself in. It's amazing how many time people on here have told others that the best way to avoid conflict is to avoid places where conflict is likely. The same thing applies here.
The only difference is that we feel that this guy got the shaft. So in defending him, there is a tendency to condone all his actions and judgments when, in other instances those same actions would have elicited a "he should have known better" response. (not really speaking of anyone specific here, just generalities)
Bottom line any adult should be able to escort a family member to a party and home, wheather drinking is invovled or not. He did nothing wrong except not meet the ethical standards of some Judge that probably never been attacked on the street.
Not just drinking, but underage (read illegal) drinking.
Again, choose your battles is good advice, but there is a difference between passing by the litterbug (or pick your minor infraction) and actually attending an event where (a) there is underage drinking and (b) there is a higher likelihood of trouble.
Again, just to be clear. Given the story (facts?) provided, I think the guy got a bad deal. I also think he showed poor judgment by being there.