...concrete answers. One can only try to connect the dots, apply reason and logic. It is like a Detective on a dead murder case; constant alertness to any clue down the road and sometimes the truth begins to surface.
I don't pretend to actually KNOW the answers, but my sense of logic, reason, and human nature as well as the desire for self-preservation on the side of the Earps and their poor choice of friends tells me there is real truth to the story.
I do believe that Holliday was involved as thought, in the Benson stage attack. Frank Vaughn described the belief that the McLaury's and the Clantons were at Drew's that night, as he said they had stopped there overnight as they were moving cattle to the Sulphur Springs ranch of the McLaurys. Drew's was a popular stop-off for all kinds of people and it would be ideal for a stop when moving cattle and needing a place to rest horse and man. Cattle move slowly or you lose weight which means money, so you do not push too hard. I assume the men were camping nearby with the cattle to keep them contained, therefore, they would easily have heard the shots associated with the attack.
Apparently, the stories relate that young Billy Clanton hung out at Drew's quite often. Maybe the daughter was an attraction or maybe he just liked the friendly atmosphere. Charleston was another favourite of his. But he seems to not have been seen around Tombstone very much. Behan didn't know the boy well as he guessed his age way off, though Behan knew Frank and Tom fairly well and Billy was very close with Frank. Also, the day of the gunfight, Billy did not know where the West End corrals were though they were on the main business drag and the town was not that large.
Fellahy's comment in his testimony that he wanted to warn Billy Clanton to get out of town after Fellahy had been near the Earp group shortly before they went down Fremont is another thing that pulls Billy into the whole thing as a possible serious witness against Doc as the two McLaurys were dispatched immediately and then all three Earps concentrated on finishing Billy who was compromised and the only real gunman left. Sounds like over-kill to me.
Even though many ridicule Ike's reference to the Earps' approach later on regarding the Benson hit, they often forget a thing or two. All those ranchers probably pretty-well knew Holliday had done the deed and the Earps were involved. But none of them said anything which is typical of the way cowboys of the day handled things. So it wasn't till July, I think, that Holliday approached Ike in a bar and mentioned the connection between him and the other guys involved. Holliday drank too much and talked too much, and he was the first one to approach Ike on the subject.
Ike didn't want to talk about it, but now the Genie was out of the bottle because Holliday couldn't keep his mouth shut, especially as he probably told Kate about it in April, because how else would she even know? So now Morgan pursues the matter a few weeks later because he wants to know what Ike knows. Then Wyatt follows up later with a deal.
In my mind, the plot thickens!