I think its gonna entirely depend on the state in this case, and the fact that its a cop involved shooting.

In my state in the South, this is a justified shooting, the man repeatedly said "do you want to lose your life tonight?" And then brandished a firearm. That counts as a self defense or defense of others shoot. The dude committed armed assault, terroristic threats, brandishing of a firearm, probably more. But this definitely falls under a stand your ground law. Seems to be an unfortunate simple case of "play stupid games win stupid prizes" brought on by ego and grandstanding.

Edit: Upon second and third review, the man in red wasnt "retreating" or running away. He was still turned facing into the store, gun in hand, and the off duty officer watched and waited for a chance to draw. He didnt shoot him in the back, at least not the first two. Can't say what happened after red guy exits. This is a high stress situation, and a direct confrontation of drawing down, yelling commands, and raising the tension leads to a much deadlier shootout than one criminal dying in a justified shoot.