He appears to have been skimming police communications equipment with his cell phone.
Skimming police communications equipment. https://theconservativetreehouse.com/2020/06/06/buffalo-officials-duped-by-professional-antifa-provocateur-arrest-and-charge-two-police-officers-righteous-police-team-stand-together-and-walk-out/
When you've reached for the cop's side-arm you're basically telling the cop to treat you with an entirely different protocol.