There was an interesting anomaly in that scene:

Michael was frantic to get Fredo on the plane with him that would take them out of Cuba. But, in the Vegas scene, after Tom tells Michael that he thinks Fredo's in NY, Michael simply tells Tom to get word to Fredo that he knew Roth misled him, etc. Since Michael was so anxious to get Fredo on the plane, probably less than 48 hours earlier, why didn't he order Tom to bring Fredo to him immediately? He waited until after his Senate appearance to tell Tom that he wanted to talk to Fredo.