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The upfront reason that Frankie changed his mind is that his brother's presence at the Senate hearing shamed him into remembering his vow of omerta. Many on these boards believe that his brother's presence also represented a threat: if Frankie squealed, his brother might be harmed. Some here have seen earlier script treatments that suggest that Frankie had family in Sicily that his brother was taking care of, and that they'd be endangered if he went ahead with his testimony.