Once given immunity for a Grand Jury, you no longer get to claim the 5th Amendment privilege and it becomes VERY easy to be found guilty of perjury if you aren't entirely truthful because the Grand Jury is going to also be seating any and every other person with knowledge of the same issues and if everyone's story don't match, someone's going to wind up doing time.

The real risk here, I fear, is he might somehow be able to pull a Oliver North and take blame for everything himself now that he can't get in trouble for it. Boy was that ever a shitshow and all it did is provide Reagan with "Plausible Deniability". I F'ing hate those words.