Baited Moped Theft Prank Knocks a Guy Out

These bait pranks are becoming more and more common. You basically leave a bike or moped out in the open and wait for someone to steal it. Once they take off you follow and when they're suspecting it the least you flip a switch and blow up a hidden air bag under the seat to scare the living hell out the would be thief. However, this guy looks like he clearly suffered a head injury when he hit the ground!