What if there was a third shooter? What if he was instructed by Roth/Ola to take out the other two after the deed was done?
Just blue skying here, think the bank robbery scene at the beginning of the Dark Knight....
After I posted a few days ago, that thought did come to mind again.
Wouldn't it be the case that Fredo would have some sort of "crew"? Yes, they might be a token group of heavies, as much to watch over the Don's idiot older brother as to carry out any kind schemes, criminal or otherwise. Fredo was running hotels, so clearly he had people under him.
What if it wasn't just Fredo who was turned by Roth and Ola, but some of Fredo's men? I can well imagine Fredo not having the stomach to kill the shooters, but one of his lieutenants might have pulled the trigger on his orders. That would satisfy the requirement that whoever killed the two shooters was in the Nevada compound, that Fredo was knee deep in the plot to kill Michael, even if he didn't think Roth was actually plotting assasination, that Fredo himself clearly wasn't gutsy or clever enough to make a play like that on his own, but to cover his own butt, he needed to get rid of the shooters. Fredo is stupid, but not that stupid.
Beyond even that, if Roth and Ola were using Fredo to get at Michael, if I were them, I'd be turning some of Fredo's subordinates. Getting those guys into the compound to kill Michael was a dangerous gambit, and I doubt anyone as smart as Roth would leave the whole plot hanging on someone like Fredo Corleone. Presuming they couldn't get at Michael's inner circle (which Fredo clearly and explicitly was not a member of), the next best thing is Fredo's inner circle, some of which would have been with him at the party.
