In that case, a defendant pled guilty in front of the judge after a FRCP Rule 11 colloquy, then tried to withdraw his guilty plea. Even though the court denied it, it still held a two day hearing
Bad news - Sullivan is citing to a case that looks a lot like Flynn's, where the defendant tried to withdraw his plea, lost in court, lost on appeal, and stayed in jail.
This will need to be an *affirmative* defense of being *innocent* (not just not guilty), that is legally sound, as well as factually accurate. Flynn has never done this - yet - to the lying to FBI charge.
That's going to be a very heavy burden, as there was almost certainly no error in the taking of the plea given the factual record.
Flynn will have to show that the gov could still go to trial and not be adversely impacted - e.g. loss of witnesses