He lent a car to a young friend, who then got drunk and hit a car. The cops came, he booked it, calling shecky-poo along the way. Kid ends up getting caught, Sheckler reports it stolen soon after (late at night- why would he notice then?) claiming the keys were in the ignition- which makes it possible for somebody to steal your car and have the keys at the same time. If the kid had gotten away, they'd all be scott free.
It might not be true, but when they say the cops are investigating the driver's relationship to Sheckler, that is what they are investigating.
That kid is fucked either way, but if he really did steal and joyride the shecklermobile, you gotta give him some credit.