>>4255455 (lb)
Power was at the UN and had 24/7 access to foreigners who could contact Trump's people with scripts loaded with code words to trigger a FISA look. That's my guess.
I think, too, that Nikki Haley dug out a lot of stuff about what Power was doing. They got Haley out of Dodge before the SHTF. Power could be a weak link, too. Has kids, will deal.
Spitballing.