I can't imagine Judge Sullivan, being a Clinton appointee or not, is happy with the fact that he, and his court was jerked around for all these years with what the DOJ has now declared an illegal case from the beginning. He was lied to by the prosecution from day one, and his courtroom used for political purposes. And he went along with it because he was gullible enough to think it was all on the up and up. It makes him look like a fool, that doesn't know what is going on in his own courtroom.
Judge Sullivan is on record telling Flynn you sold your country out.
If this case had respolved in the typical way, with DOJ deciding to drop it (assume gulity plea withdrawn) on burden of proof, both sides would persist in the old narratives. Flynn would still be guilty, not tried, and Flynn would be innocent.
This move cuts that off. This move kicks Team Mueller and the FBI team that framed Flynn, out into the cold. DOJ is disowning Mueller. I believe this is the first time in histoiry that a SC has been exposed as corrupt.