Giancana was in a trap and there was no good options for him. He had spent a year in jail for refusing to answer questions before the grand jury. He knew he was going to be called back when the grand jury reconvened. He had four choices (IMO):
- talk and the Outfit would kill him. He knew the rules about talking.
- refuse to talk and go to jail.
- try to "skate" around the questions and be evasive. This would be really tough because the prosecution had tapes from the Armory Lounge and Celano's that recorded Giancana talking about killing people, etc.Giancana had immunity but he would be forced to implicate others.
- get out of Chicago and the U.S. This was his choice because the other three were no good.

He returned to Chicago when Robert Kennedy and et al pressured the Mexican govt to kick him out. Keep in mind that Giancana still had a representative in Chicago while he was in Mexico. Butch Blasi was his rep. I'm not sure how long his involvement was recognized, but he was still involved for some period of time. He made an enormous amount of money during his time in Mexico, but refused to share any of the money with the Outfit.

Once he returned to Chicago in '74 his power was greatly diminished. When he agreed to testify, his days were numbered. I believe he was only required to answer questions about Outfit activity that occurred after 1972. He testified four times and was preparing for a fifth appearance when he was murdered. As far as I know his testimony is sealed and has not been made public. So is Phylis McGuire's testimony.

I don't think anyone has reported the results of what transpired behind closed doors in front of the grand jury.