Distilling complex legalities into 140-character tweets is next to impossible and the "threaded" tweet storm can only do so much. That said, I put this together last night when word broke that retired General Michael Flynn is seeking immunity from prosecution in exchange for his testimony before Congress (and, presumably, federal prosecutors).
A few additional thoughts here: First, the very public announcement of this "offer" indicates a couple of things to me - that investigators have already been in touch with Flynn (or his lawyer), that he has likely turned over some documents and/or had preliminary conversations about what legal jeopardy he may face; Second, that his after-the-fact registration as a foreign agent was done to mitigate some of that jeopardy in the same way some colleges "self-sanction" before the NCAA has a chance to drop the hammer in hopes of getting leniency; and Third, that Flynn *potentially* has that proverbial "story to tell" that would burn the city down.
Keep in mind, prosecutors are only interested in flipping potential defendants if those smaller fish can offer up someone bigger - in this case, the only person of substance above Flynn in the Trump campaign/administration is Trump himself. Of course, prosecutors don't just hand out immunity deals - as my tweets note, a proffer with accompanying support would have to be made about what Flynn is prepared to testify to. Further, because prior prosecutions, particularly during Iran-Contra, were fouled up by public testimony before Congress that was then used in the prosecution of people like Ollie North and John Poindexter, federal prosecutors would likely request that Congress NOT go forward with any interview or hearing that included Flynn while their criminal investigation is ongoing.
All in all, this is REALLY bad news for the Trump team and a (possibly) major step toward a fuller understanding of Russia's interference in the election coming to light. On the other hand, this could also be the effort of someone about whom we have a lot of public information - the undisclosed foreign representation and conversations with Russian officials being foremost among them - that would already establish probable cause of criminal activity. In other words, this might also be Flynn trying to protect himself from misdeeds that have little/nothing to do with his actions on behalf of our President.