“CCW holders can’t shoot someone who might throw a knife at them, neither should cops be allowed that privilege.”
A good case can be made that someone making motions to throw a knife at someone else is a deadly threat and therefore they can be shot legally to protect life or to protect from great bodily harm.
Saint Anthony brought his death on himself by resisting arrest using deadly force.
Then it is acceptable to shoot someone threatening to throw a baseball bat at you?