One thing to understand is that police are trained to take defensive action against an aggressive individual who is within a certain distance. Within that circle, an unarmed individual can reach and overpower an officer before he can draw his weapon. So even if you are unarmed, if are acting aggressively and you approach an officer you are likely to get shot or at least tased/pepper sprayed. If you ignore an order to stop where you are and put your hands up, and you continue to approach you are likely to get shot.
Now, at least on the surface this does not appear to be exactly the situation in the recent Minnesota case. But we only know what's in the media, and the media likes to sensationalize and report half the story.
That said, if a cop has his weapon drawn on you, do not move. Do not twitch. Keep both hands in view. Do not do anything that you are not explicitly asked to do.