Someone gave them a wake up call. There's a video on C-Span showing Greenberg saying the AIG bailout was not necessary and that bankruptcy was a valid option without a financial meltdown.
"One White House official with knowledge of the conversations told me that the Russian ambassador raised the sanctions to Flynn and that Flynn responded that the Trump team would be taking office in a few weeks and would review Russia policy and sanctions. Thatís neither illegal nor improper." ~ Bloomberg
When do we get to see the transcript? Flynn, being in espionage, had to know his call was being recorded too.