It's not credible to claim that Good got in her car that day with the intent to run over ICE and cause a mass casualty event. Her actions immediately preceding her death were 1) parking her car perpendicular to the road, rather than lining up with officers and building up speed; and 2) waving at and talking to her killer-to-be.

Whether or not her car made contact with her killer, no reasonable person would assume she had any desire to run him over. There's also no reason for anyone to believe that shooting her as she drove past prevented an imminent mass casualty attack.

So then your argument boils down to: if you brush against law enforcement with your car, even by accident, they should kill you on the spot in retaliation.