You're called to a commercial building at O-dark-thirty because a passing motorist noticed a suspicious person peering through the windows of the building. You are alone, and your nearest backup is at least ten minutes away. You arrive and locate the subject. In this case, I contacted this person with my weapon drawn from behind what I'd would call moderate cover/concealment (a dumpster). I illuminated him with my flashlight and identified myself, and ordered him to show me his hands. He responded by shining a small, but fairly powerful Maglite in my eyes. He refused to drop the light.
So, here we are in a standoff of sorts. I could not see him, especially his hands, he could not see me, and he would not drop the light. He refused several more commands, but finally complied when I told him he was about to be shot. I would have shot him in those next several seconds too. Do you think I would have been justified?