Sure he did. He could have pulled out the gun so the aggressor saw it. Could have said “stop or I’ll fucking kill you.” All while continuing to walk backwards and creating space.
If the person keeps coming after you’ve said that, that’s what you can hang your hat on at trial: you knew your life was in danger because the assailant had no fear of death. You could at least say you feared the guy wanted to take your gun and kill you with it. Evidence was that the guy in the article shot immediately upon drawing and didn’t give any sort of warning. He apparently took a few steps backwards, said stop three times, and then drew and instantly fired.
I think the fact that the police arrested the guy, the prosecutors put the case on, the judge didn’t dismiss the it after close of evidence, and the jury was nearly deadlocked, show, that the charges were reasonable in this case. Certainly the jury is in the best position to decide the facts and apply the law.
The thing that may have saved him is that he fired only one shot and the aggressor lived. You’ll notice he was not charged with attempted murder but rather wounding in the commission of a felony, or something like that.
I wonder if the aggressor will pursue a civil lawsuit for assault. Sort of how OJ was acquitted in criminal court but then found civil liable; the criminal standard is one of reasonable doubt, the civil one of preponderance of evidence. Certainly both parties could be found liable under negligence, if the parties sue each other.