The Lie: Hands up. Don't shoot.

[Dystopia]

Does that justify killing him?

Justification doesn't enter into it.
The cop is not a judge, he must follow his training, and the training that cops receive tell them to use deadly force, IE shoot and kill, someone that tries to take their side arm from them.

If you don't like this training, then push to change the training given to police.

[emphasis mine]

Only in America because the ideal training for a cop teaches them to use deadly measures when their life is clearly at stake and not when they think they might remotely be in danger - Cops are taught to use all kinds of methods to immobilize targets and deadly force is usually a last resort - I.e. When someone points a pistol against the cop (and even in this case cops in my country are taught to shoot legs instead of heads/chest). The important question here is to know what happened specifically and if it justified killing someone - Your instinct and sixth sense are not evidence that someone's about to kill you (nor the colour of someone's skin) - Only empirical observable acts that clearly denote the intention of violence against you or an innocent person should be considered appropriate to fire a shot