You are just too wedded to your brandishment=firing from a legal viewpoint. Just as there are varying degrees of assault that carry different penalties depending upon the severity of the assault (and assault with popcorn would have to be at the very bottom), improper brandishment carries a much lesser penalty than 2nd degree murder or manslaughter:
In Florida, it is a first degree misdemeanor offense punishable by a maximum prison term of 1 year and a maximum fine of up to $1000, if you are found guilty of an Improper Exhibition of a firearm.
That is the salient point you refuse to acknowledge. Had the shooter instead brandished and there wasn't legal grounds to do such, Reeves would be facing misdemeanor charges, instead of life in prison.
I do acknowledge that.
Now do you acknowledge that it is not reasonable to suggest brandishing the firearm as an alternative to leaving it concealed?
Either the justification existed or it did not. I'm not aware of any distinction. Those that point out that brandishment is sometimes sufficient lose sight of the fact that it is a decision made by a person that, although they fear great bodily harm or death, they have time to decide whether the shot must be fired.
Did the popcorn thrower say, as he was assaulting the ex-cop, "I'm gonna punch your lights out"? What did the popcorn thrower's wife know that made her try to restrain her husband? If you know the answers to those questions, tell me what you know.