And, again, why go to Miami in the first place?
Michael's top priority was to buy time to find out who the traitor was in his family. He could leave nothing to chance. That's why I believe he needed to look Roth in the eye, convince him, face to face, that their deal was still good, that "Frank Pentangeli was a dead man," that he would go on to Havana and hand over the $2 million. He couldn't build a convincing case any other way except through a personal meeting.
I don't know TB. Michael's trip had to be planned before the Communion. Do you agree? However, if planned in advance, he would not have had at that time sufficient evidence of a traitor in the family. So, there wold no have been any need to gain time.
Then Ola shows up at the Communion and pretty well affirms that Roth is in Michael's corner, true or not. It's only through the Geary meeting that Mike gets any indication of a traitor. Then the shooting. Mike could have easily passed word to Roth that the deal was still on and that he thought it was Pentangeli or anybody else who tried to kill him. That would have bought him all the time he needed.
