They then opened fire. The authorities would not estimate how many rounds were discharged. Mr. Gainer, the sergeant-at-arms, said he believed that five to seven officers had fired.
Possible Clues in Fatal Chase, but No Motive — Miriam Carey Was in Car When Police Fired, Official Says
Maybe contagion, but many of us know full well that it can take a bit of time to know if you're actually scoring hits with a handgun. Look at this guy run to his car and take off during the Oregon state trooper shooting. I had no idea he'd been hit until I read the articles. He's moving pretty well for a guy with a fatal chest wound.
youtube.com/watch?v=q1gYEG1TzBk
If you're in the situation, and you've got a shot, and the threat is continuing, you can't be assuming someone else will take it.