Originally Posted by Often1

This is simply sound practice, whether it is required by law, company policy or common sense. At FL 40, it is not simply a matter of tossing someone off the bus.

The standard usually has nothing to do with "drunk" and everything to do with "appearance of impairment".

I expect CC on long-haul flights in premium cabins to monitor alcohol consumption and cut someone off well before they become a problem.

While conversations should not have been overheard by pax, the fact that CC communicate with each other is important and good.