Also, the knife cuts both ways. Fredo could testify about Roth and Ola and who knows where that would lead.
Come to think of it all Fredo knew about Roth and Ola was that Roth was straight laced, Ola knew Havana like the back of his hand, and that Ola told him Michael was being tough on "the negotiations" and thee would be something in it fo him if he helped.
"Io sono stanco, sono imbigliato, and I wan't everyone here to know, there ain't gonna be no trouble from me..Don Corleone..Cicc' a port!"
