I think this will prove to be significant.👇 
Here's my theory (note theory, just floating to see if we can dig to prove/disprove):
Sergei aka as person 1 was at one time an Intel asset of some type either for CIA or a cooperating country, similar to C.P.
The CIA knew this, knew for a fact he was not RIS.
Sergei aka as person 1 was at one time an Intel asset of some type either for CIA or a cooperating country, similar to C.P.
The CIA knew this, knew for a fact he was not RIS.
Someone (redacted) likely an other or foreign Intel outfit gave the FBI some document claiming Sergei was probably RIS, someone also suggested this to Simpson.
All the while it appears the whole time the US Intel group that had a prior or on going relationship w/ Millian didn't tell that to FBI (or did and it was ignored).
Its the only explanation for why Mueller never bothered to interview or pursue Millian. It also explains why after trying to pass off Millian as the source about to be outted, Simpson changed course, someone clued him in.
Nobody fully explained this to the IG. But I'm pretty sure Durham knows.
