Raising the skateboard is likely display behavior; like a cat arching its back and hissing. Display behavior is intended to avoid a fight by appearing to be too tough to tackle. It’s the wrong response when facing a cop with a gun. The cop, especially now, must assume he’ll be beaten if he does not respond. Also, the cop is required to stop the theft. It’s part of the job.
Maybe not just display behavior since one was holding the policeman down while the other was raising the skateboard.