I must admit I'm disappointed with you Charlie. If you are truly innocent then you must not plead guilty to *ANY* charges that you did not commit. We cannot permit the Federal Mafia to simply threaten everyone into submission. This sets a very bad precedent for the future and other Bitcoin users.
You need to take your chances of winning at trial into consideration. If there is evidence against him and the potential penalty is great then it would be better to accept a guilty plea, especially if the plea deal would likely result in no jail time.
No one ever wins at trial.