Very sad, I am one of those fellows that will keep a gun on me when answering the door late night. I also have a way to see who is at the door, not sure this fellow did (or not). I don't open until I know what I am opening to. If this fellow didn't have a way to look out and was "blindsighted" with a flashlight in the face, how the heck is he to know what he is facing. I don't like the flashlight at all, it is like the thugs in Seattle shining laser lights, it limits how you can respond.
The fellow obviously is like me, you don't "hard drop" your gun, it is dangerous to do so, you lay it down. I can't fault the fellow in his reaction at all. He was doing his best to not damage his gun, lay it safely down, and be submissive with very little time to process things. Also they did say they were police, but NO it was not loud enough to make sure he heard it. Yes you can hear a knock better than a voice going through a door.
Police officer, in a rock and hard place, but my gun (and I assume this fellow too) is legal for me to carry especially in my home. I understand their need to be safe, but they sure didn't give this fellow much space to comply (and time to process it). The hand putting the gun down was hidden from the fellow that shot, he was to protect his partner. Unfortunate. Seems to be nice police that were not being rude (from way he talked to the lady).
What have I learned from this video (already knew)... Know what you are opening your door too. BEFORE you open door, at least verbally know what you are up against... In this case, if the deceased had took a little more time to id his surroundings he probable would still be alive. Even though it was no fault of his own his death occurred (other than perhaps being more respectful with his volume at night).
Things we can not just assume here... They might of been fighting and the caller may of been correct even though she claims differently. Slamming doors etc is not usually something that occurs unless someone is upset.
We can also not assume the caller was telling the truth, as pointed out, he did make a comment to the effect of whatever makes the police come quicker.
Do I think the police are at fault here? Nope, but dang I would want that flashlight rule looked at. The fellow was putting down his gun and had no clue he was doing it where the other police officer could not see it as highly suspicious/dangerous.