So his not implicating Tom and his only answering specific questions and testifying that he never recieved a direct order from Michael tells me that Cicci was placed under arrest but DID NOT turn states evidence or make any kind of deal with the government.
He could have copped a plea to do a long sentence in exchange for testifying that he was a "button" and that he murdered people at the behest of his "superiors," but he could not finger Michael, and they probably never asked him about Tom.