...I think you are being a little unfair in assuming Ike was 'shooting off his mouth' to anyone he could. Actually, other than the episode in the courtroom after Virgil arrested him, no one who witnessed Ike spoke of him being loud or belligerent. Even the clerk in the courtroom said Ike was quiet until Wyatt accosted him and Morgan threatened him. Naturally, he responded! But he did not shout!
I've lived among old timers on the ranches and I never knew one that was loud unless something funny came up. When they spoke, they were straightforward and meant what they said. They never backed down from anyone no matter what the risk and they never asked anyone for help either. This is characteristic of such men. Ike was no different.
True, he was spoken of as being in a couple of saloons and he did have a few drinks with some guys and he did complain about the way the Earps had treated him. But no one accused him of threatening to KILL anyone; just that he was ready for them if they wanted trouble.
Also, not ONE person said Ike was drunk in testimony; neither one of the Earps did either, but Wyatt did say "Doc was pretty tight." Two witnesses were questioned about their drinking but no lawyers on either side questioned Ike about the same. There was no reason to, apparently.
When Ike went to Hafford's saloon because he was looking for the Earps, Hafford did not say Ike was loud, angry, or drunk. So let's be fair and examine what really went on.
I appreciate your reference to memories tricking us quite easily, especially as we get older. But on the other hand, consider Behan's position and stress level. He has just been rebuffed and it is apparent serious trouble that is out of his control is at hand. As Behan makes his way into the lot he is near Claibourne at the time shots ring out, he reacts by grabbing the kid and gets him into the back door so in the moment of shifting his attention it is not hard to understand that such confusion as to which pistol was in which hand is a given.
That is the way I see that particular situation. Not everyone does. I feel a great injustice was performed, as I said before. Justice is my motivation, not trying to be a 'cowboy' supporter, but I know a little about how they conduct themselves and why. My father-in-law was a remnant of that very frontier and his older sons as well. That's why I THINK I understand them and reject completely the silly Hollywood versions. No real cowhand I ever knew would talk or act like those guys in the movies. By the way, they all liked their hair short!