Not many people watch them, but there are countless videos of police stops where it's not the police drawing a gun, but the driver of the car pulled over. Often it's not just pulled- it's aimed and fired. Some cops die, thankfully many get hit in the arm and it's non fatal.

It happens so much in the United States that you honestly can't blame the vast majority of at least being ready. That's not saying there aren't cops that are TOO ready and unclip the holster just walking up to the car.