Yes and no, Judge Sullivan did toss the conviction of Sen. Ted Stevens back in 2009, excoriating the prosecutors and demanding an investigation of prosecutorial misconduct (which of course went nowhere with the vile Holder Dept of Justice).
But if Sullivan were to do roughly the same thing now, tossing Flynn’s plea agreement and throwing out the case with a strong rebuke to the Mueller team, it could give Team Trump some valuable ammunition at last.
If anyone is likely to deliver the justice that we are looking for, it’s Sullivan. So that is in Flynn’s favor. I just wouldn’t get my hopes up.