TB, the only problem with your reasoning about Michael's message to Roth is that Michael's trip to Florida to see Roth had been arranged before the attempted assassination and, thus, Michael's use of Buscetta was prearranged also.
Oli, I don't believe Michael's trip to see Roth in Florida was pre-arranged. I think he arranged it after the Tahoe shooting as a way to make Roth believe he thought Pentangeli was behind the shooting, not Roth. Almost as soon as he comes inside Roth's home, he says: "I came here because there is gonna be more blood shed. I want you to know about it before it happens so that there's no danger of starting another war." Then he tells Roth,"Frank Pentangeli came to my home and he asked my permission to get rid of the Rosato brothers. When I refused, he tried to have me killed. He was stupid, I was lucky; I'll visit him soon. The important thing is that nothing interferes with our plans for the future. Yours and mine."
I believe he called in Buscetta after the shooting.
