That rule was carpet bombed nightly by the time I was hired at the end of the 80's.
Standard FAR drinking rule, 8 hours. FYI, by now we all know it's the blood alcohol level that can nail you even if drinking outside the 8.
A couple of our guys found that out the hard way with the Brits.
No jihad or secret monitoring of new hires. Just remember that bar cameras, credit card receipts and electronic hotel doors don't lie. Stay away from "freebies" off the jet also. Bar codes and lot numbers off minis probably don't either.
Pretty easy line to walk.