Good point. But what is even more curious is how did Michael intend to assassinate Roth. As he told Fredo, Roth will never see the new year. Well, when Michael told him that, Roth was not hospitalized and there were no plans to hospitalize him. So, where and how was Roth's murder to take place?

I disagree with TB about the timeliness of Michael's escaping Cuba by plane. There was no reason for Michael to attend the reception because once there, he could not be assured of being able to leave. You might also notice that Michael's departure from the Palace seems to be prompted not by a prearranged plan, but by Michael's assessment of the military situation from what Batista was saying. In addition, I don't see why Michael would have to have an alibi of any sort regarding his whereabouts during Roth's murder.