Recently, a routine police patrol was parked outside a local
neighborhood bar in Minnesota. Late in the evening, the officer noticed
leaving the bar so intoxicated that he could barely walk. The man stumbled around
the parking lot for a few minutes with the officer quietly watching.
After what seemed an eternity and trying his keys on five different
vehicles, the man managed to find his own car which he fell into. He was
there for a few minutes as a number of other patrons left the bar and drove
off. Finally, he started his car, switched the wipers on and off (it was a dry
night), flicked the hazard flasher on and off, tooted the horn and then
switched on the lights.
He moved the vehicle forward a few inches, reversed a little and then
remained stationary for a few more minutes as more patrons left in their
vehicles.

At last he pulled out of the parking lot and started to drive
slowly down the street. The police officer having patiently waited all this
time, now started up his patrol car, put on the flashing lights, promptly pulled
the man over and carried out a breathalyzer test. To his amazement the
breathalyzer indicated no evidence that the man consumed alcohol at all.
Dumbfounded, the office said "I'll have to ask you to accompany
me to the police station. This breathalyzer equipment must be broken."
"I doubt it," said the man. "Tonight I'm the designated decoy."