If you or I pulled a gun and then shot someone, it wouldn't matter how much we argued that it was an accident.
"I'm sorry your honor, I only meant to tase him. I didn't realize that the totally different carbon steel Desert Eagle 12-round pistol had been drawn instead of the aluminum and plastic stungun. My bad."
That argument is as bullshit as the indifference the police [and pro-police conservatives] hold towards human life.
America on the whole views it as acceptable to kill people who are in your way, offend you, or don't gleefully adhere to the laws passed by a corporate-controlled congress of White Anglo-Saxon Protestants (WASPs).
That a nearby BART cop uttered the N-word means nothing, of course. An astonishing 39% of CNN polled respondents believe the police shouldn't be charged with anything. After all, the victim isn't a rich white dude.
Rights only apply to people who deserve them. That's the tenet of all well-established governments thus far in human history. I'm not an advocate of this school of thought, and the wiser among you detect my sarcasm.