I'm with you on that principle, but in this particular case he just got the drop on the cops. He got two motorcycle cops when they pulled him over, then he shot through a closed bedroom closet to get the other two. You better believe they were being completely careful with guns drawn, and they still lost.
It sounds like there was a training or experience issue with those policemen, especially the second two. Prudence would seem to dictate proactivity and good body armor when looking for a known “cop killer” in a close environment. It is a shame that these men died, and I have to believe that, this happening in Commiefornia, their system bears a lot of the blame.