birkenfeld's information to go after ubs, the justice department was closing in on his biggest client, igor olenicofffor tax evasion. olenicoff cooperated with the investigation and paid $52 million in fines and back taxes and got off with no jail time. but because birkenfeld hadn't prosecutors told about his relationship with olenicoff, birkenfeld was arrested and charged with conspiracy to commit tax fraud. he pled guilty and was sentenced to 40 months in prison. and he was not happy about it. >> and you think that you should not be going to jail? >> i think i shouldn't. >> even though you violated the law, and you were an enabler. i mean, you were the person who were implementing these policies. >> and i'm the only one going to prison out of 19,000 accounts, and no swiss bankers. >> did your investigators believe that birkenfeld was telling them everything he knew? >> we were certain that he wasn't telling us everything that he knew. in fact, he told us that it wasn't everything that he knew. and at his sentencing hearing, his lawyer admitted that he wasn't forthcoming with us. and in particular,