We had such a lecture a few standdowns ago (last summer IIRC), given by some local PD guys. A class ahead of mine was responsible for giving the demo, where the first guy drank 1 beer, the second 2 beers, through the 6th guy who polished off 6 beers in a couple hours. When they called them up on stage, each had to do the field sobriety tests, and every one of them passed except for the last two. Of those two, the cops said they wouldn't have even guessed the first one was drunk, and wouldn't have given the field test. Hilarity definitely ensued, though I think the command learned it's lesson about that one.....or at least involving the local authorities.....still haven't figured out what it takes to actually get pulled over by them (perhaps open container dangling out the window along with a firearm). Did I mention there were 2 open kegs for all hands on hand for the event? Gotta love it