On a related subject, the ongoing relationship between Fredo and Roth would have been further reason for Michael to have him killed.
Yes. In addition to making that (fatal)outburst against Michael in the boathouse, Fredo revealed that he knew Pentangeli had survived, and that Questadt belonged to Roth. Michael had to figure that Fredo could only have gotten that info from Roth--and that Fredo had deliberately withheld that info from Michael, even though revealing it before Michael's testimony might have rehabilitated Fredo in Michael's estimation.
Also I wonder if Roth and his people had a hand in getting Fredo out of Cuba. Fredo was certainly no genius, but somehow he apparently made it to New York. When he got there maybe the Rosatos took care of him.
I posted on that subject here:
http://www.gangsterbb.net/threads/ubbthr...true#Post472494
