BB, if you're right that Michael never believed that Fredo had anything to do with the shooting, then how do you explain the fact that Michael had Fredo killed?

As to whether he HAD to kill him, that's a little more debatable. I don't entirely agree that Fredo was a threat as long as he was alive. How much did he really know about Michael's security operations? Obviously, enough to get Roth's people onto the compound. But did he know anything that couldn't be changed after he was send into exile?

I've always felt that FFC wanted us to think that the killing of Fredo was not absolutely necessary. Rather I think FFC used it to show how inhuman Michael has become.

SB, I think that if Michael was indeed sizing up Fredo over a few banana daquiris in Cuba, than he missed out on a telling remark. When Fredo wonders why they didn't do that "before" I always thought that was a clue that Fredo had done something that would irrevocably hurt his relationship with Michael. Michael doesn't seem to pick up on that nuance, though.