At closing time, he sees a biker stumble out of the bar, trip on the curb and fumble for his keys for five minutes.
When he finally gets on the bike, it takes him another five minutes to get the key in the ignition.
Meanwhile, everybody else leaves the bar and rides off.
When he finally pulls away, the cop is waiting for him, pulls h im over, and gives him a Breathalyzer test.
The test shows he has a blood alcohol level of 0.0!
The cop says, “How is this possible?”
The guy laughs and says, “Tonight I’m the designated decoy.”