i fell backwards into reading some about Michael Flynn's "business" in Turkey, via Turkish subjects, and it sounds like the Reza Zarrab flipped and turned on Flynn for Mueller from the minute he was contacted in part to make sure that the U.S. tries Zarrab
Erdogan started wanting him publicly back in 2017 suddenly after the U.S. charged a bunch more Turks for similar crimes...originally it was just private "backdoor" asking for him, including apparently both Erdogan and his wife accosting Biden and his wife at a reception where Erdogan was seemingly confused when Biden said
he couldn't just fire the prosecutor and end the case*
*when Khrushchev came over to the US, he repeatedly asked the Eisenhower White House what they were going to order the press to report and not report about his promotional trip around the U.S., Khrushchev was similarly baffled at the White House's response of "why would we order local papers what to publish about your trip?" and subsequently how positive the press was about his trip