I hadn’t been paying a whole lot of attention to the Flynn stuff, including who was source:

Last night Robert Mueller’s prosecutorial team - which apparently still exists on some level - made a court filing in the Michael Flynn case, despite the fact that it wasn’t under obligation to do so, and it wasn’t even close to being up against any deadline. The filing revealed that Flynn witnessed Trump and his underlings commit several crimes. This in turn prompted the judge in the case to order that far more evidence of these crimes be publicly released soon. This, of course, wasn’t coincidence.

With his filing yesterday, Mueller is essentially unredacting the most important pieces of his own report by force, in a way that Attorney General William Barr can’t stop. If Mueller had publicly testified on the 15th as originally planned, would he have been legally able to discuss the Trump crimes that Flynn witnessed? But now that Mueller has found a way to force the Flynn stuff into the public purview, there’s nothing that Trump and Barr can even try to do to stop Mueller from testifying about the Flynn stuff