Bsdetection, nothing explosive about the bombshell.  Smart move by Flynn, if true.  Here is why.  Let’s assume the FBI and Congress grants Flynn immunity from prosecution in exchange for testifying about his knowledge of Trump campaign’s ties to Russia.  As soon as the ink on the agreement has dried, Flynn will raise his right arm and swear to tell the truth.  He will then say he knows nothing about it and will say that is the truth.  Since he will have complied with his part of the immunity agreement, the FBI will not be able prosecuted him for whatever it has on him unless the FBI can prove he lied under oath.