Cops don’t have to wait for you to shoot in order for them to draw their guns and return fire. It’s understood that they may not get a chance to return fire if they have to wait to be fired upon.
It’s no different for you, as a citizen. If somebody has their weapon drawn on you, you don’t have to wait until you’ve been fired upon to return fire.
Huh??? I'm not going to draw on a guy who has a weapon pointed at me...Neither is a cop...