We can only go on what the video shows. The guy doesn’t appear a threat.
On the contrary, He actually looks
very threatening.
He has just had a gun pulled on him.
Somebody trying to supplicate, I would expect, would hold his hands up, palms outwards and slowly back away, offering apologies as he does so.
This guy doesnt do this.
He backs off, but only one step or so.
His legs are apart,
And his hands are not "Up", his arms are by his side and held slightly wide.
This is all preparation for action, not preparation for walking away.
While in the absence of independent witnesses, we cannot know for sure what was said, It is inconceivable that words would not have been exchanged immediately prior to the actual shot fired.
If you go back to the beginning, we also see that after the initial assault (A very hard shove indeed, Not a gentle push where the victim simply lost his balance) The Guy pulled up his shorts, Also a preparation for action. I have no doubt in my own mind that had the old guy not pulled the gun at this point he would have received a severe beating.
Once the gun was drawn this was only ever going to go one of two ways.
Either the assailant would have walked away, or the old guy was going to shoot him.
The old guy could not lower the gun unless the assailant walked away first or he would have certainly been attacked, severely beaten or even shot with his own Gun.
At this point, the only person who could have defused the situation was the assailant, by walking away,
He chose not to do so, likley preferring to aggravate the situation, and got shot as a consequence.
(Interestingly, many of the on-line clips now seem to have been edited around the time the shot was fired to make it seem that the old guy shot without warning, the earlier clips clearly showed that there was a brief time when some sort of verbal confrontation must have taken place)