Stray bullets and accidental shots are just as lethal as aimed ones. The point is that someone pulled over at a traffic stop can keep a gun hidden and take the first shot if they want to. Each and every traffic stop is a nervous bundle of potential danger for a cop, and they aren't paid to endanger themselves. That's why we go out of our way to make cops comfortable during a traffic stop. Keep your hands where they can be seen. No sudden movements. Polite interaction.

It's not healthy to be near nervous cops.

So it's OK to pull a gun and shoot at a cop if you don't hit him?

Nah, someone is just playing probabilities with someone else's life. But hey, you don't have to be a cop. Better to be a webdev and hangout on Hacker News all day.