He started the car.
That's what it looked like to me. Both his hands went somewhere, then his left comes back into the frame after the shot and then it all dissolves.
I believe the cop will state that he became suspicious that the suspect had stolen the car or was transporting contraband when the suspect refused several requests for license and registration. The cop requested the driver to get out and the driver made a sudden move, possibly to start the car but possibly to grab a gun or to smash the door open into the cop. That doesn't mean the cop is not guilty, just that the video doesn't seem very clear on anything other than the events spiraled out of control within the space of three seconds.
“He started the car.”
After being told to take off his seat belt, to wit get out of the car.
After not presenting a driver’s license and being uncooperative about it.
After handing over a bottle of gin (hugely visible in the extended cut).
After being pulled over for a vehicular violation.
After somehow getting the cop’s attention whereby a mere missing front plate provided reason to stop him.
The linked video does not show all of what was shown at the briefing. The longer lead-up video may help understand why the driver was stopped in the first place.
The driver wasn’t an angel. He’s guilty of 4 violations/crimes in that video alone, and the next step (get out for a DUI check) could have revealed a felony.
Driver tried to escape, cop understandably (but not excusably) over-reacted.