Well, this is another of those pain-in-the-ass script/filming discontinuities. Yes, it might have been part of a 1968 view of Michael from a discarded scene. But why leave it where it is, when there was no way Michael would have let Roth live another nine years after Havana, and the continuity is in the 1960 time frame?
Years ago, an alert poster spotted the Senate lawyer Questadt sitting behind Roth in the scene where Cuban President Batista is greeting the gringo businessmen. What was he doing there? If Michael had seen him there, he'd have taken the Fifth at the later Senate hearing. Another astute poster found an earlier script treatment (discarded) where Michael was to meet with Questadt in Havana. Evidently FFC filmed him as part of that (discarded) plot line, then left him in because the entire Havana sequence was filmed in the Dominican Republic and it would have been impossible to return to just re-shoot that snippet.
If Paramount recycled all the discarded script treatments for the Trilogy, the paper industry would never have to fell a tree again. Too bad they can't recycle movie film--must be a million feet of discarded film from the Trilogy on cutting room floors.