What's your point? People try to disarm police officers all of the time. My father, a retired cop, had many people try to go for his gun. There is a HUGE difference between going for cop's gun when it's holstered and going for a gun when it's out.
I have a hypothetical (not sure if this has been addressed or not). If Pauli disarmed Heimsness, what do you believe he would have done with the gun?
My answer is, it doesn't matter. Paul was dead either way. If he had succeed, Officer Troumbly would have, theoretically, shot him. The only question there is would she have stopped Paul quick enough before he put a couple of rounds in Heimsness.