This behavior on the part of the crew makes no sense to me. Why punish the 99% of the passengers who didn't say a word for the boorishness of one?
Because IF something happens (accident/incident), then 99% of the passengers will say, "hey, there was this one passenger who said the pilots were drunk! they had to be!"
Imagine the headache that would ensue, the lawsuits, etc.
Not worth it. If I'm ever accused of being drunk by a passenger, I'm removing myself from flight and getting tested. Clear my good name, and then we'll go flying.