Postal worker remark:
Yes. That is exactly what I'm saying.
First, let me draw a distinction. Cops is government--hard, strict standards need to apply. Plus, cops is trained. If Mrs. Nervous-nellie Neurotic shot the same man at her back door with a gun in his hand hanging at his side, I'd take into account her lack of training and Justice Holmes admonition that detached reflection cannot be demanded in the presence of an upraised knife. However, police do training precisely to fill in where there will be no time for detached reflection.
Back to the question.
Gun-at-side in this context is not intent. Insofar as it can transition to intent in less than a second, immediate action is highly advisable--draw, move to cover, while giving commands to drop the gun, etc. But, its still not time to shoot.
We've all heard the stories about the citizen who announced to the cop, "I have a gun" intending to be courteous. Some have heard about the citizen who offered his gun to the cop at the driver window, and was shot and killed by the cop at the passenger side who only saw the driver reaching for a gun in the glove box at the driver-side cop's request. Thus, just because we cannot imagine possible innocent explanations for exiting a car with a gun in hand, does not mean they don't exist. But, we don't have to imagine innocent explanations if just apply AOJ/I strictly. Pointing the gun at the cop is intent. Hanging at the side is intent of...well, having the gun in his hand.
A quick example comes to mind. Remember the youtube video of the suicidal guy who sits in a lawn chair on a sidewalk in town. SWAT sniper shoots the gun out of his hand. Gun in hand. Suicidal people are by definition homicidal. Police have learned, or maybe are learning, that suicidal people can turn their hostility from themselves to the cop in an instant. Yet, they tend not to go around shooting these people just because they have a gun in their hand. The police in the lawn-chair incident moved or stayed near cover and worked to de-escalate the situation, rather than just shoot him.
We have to be conscious that we're talking about a citizen's life here, in danger from government. We want to be very, very careful about the standards, about the justifications we accept, about the
(excuses?) we accept.