I would bet a months salary that for every pilot blowing positive on alcohol there would be 100 pilots who's performance is degraded to a greater extent by fatigue.......shame you can't measure it as easily.
17 hours of wakefulness degrades performance to the same degree as a blood alcohol level of .05%.
What does months/ years of shift work do when combined with a duty that starts at 6pm and finishes at 6am with only two crew on board?
They're barking up the wrong safety tree with alcohol.