It’s not just an admission....he’s opened up the situation where Flynn’s case is unwinnable for the government, and there’s probably going to be damages awarded eventually (may take three or four years) to Flynn.
Judge has to be standing there and wondering which idiot started this mess, and how it can end now.
The bigger question is "What's the judge going to do about his courts and lady justice being perverted by a bunch of deep state thugs?"