My experience in Norway regarding the police with respect to drunk flying is this:
They are quite trigger happy about this, and without proper verification they will confront a crew, in public, to do a breathalizer test. (In front of the airport building)
After all crew members were found to be completely sober at 5am, the police was asked why they had to undergo this treatment.
It turned out that "someone" in the crew hotel tipped them off. The LATE crew was seen having a drink in the bar at midnight.
So the EARLY outgoing crew was breathalized. To their disappointment they were sober of course.