There have a been a fairly large number of arrests in MD where police have charged the driver with video taping the arrest after being asked to stop. The police are stretching the law and a number of the cases are headed to the MD Supreme court.
Given the number of law enforcement shot in traffic stops there is nothing wrong with un-holstering his weapon. Failing to identify himself as a police officer, with shield displayed, is a big no-no.
Guy was lucky. The Ottawa Hills Police (rich Toledo, OH suburb) pulled a motorcyclist over and before the guy could get off the bike was shot and paralyzed from the waist down. All captured on the police car video. Time from the car stopping and shot being fired was 3 seconds.