She's actually a first rate investigative reporter... I wouldn't be so quick to dismiss her.
Besides, if this was the reason it would still make more sense for Rosenstein/Sessions to use the "Messed with Hillary's election" excuse as the "official" reason because that excuse pretty much disarms the Dems.
I wouldn't be surprised if Trump finally got his proof that Comey was actively helping Obama and the deep state with the spying on Trump and his people... but Trump can't use that as the reason for firing because Dems would claim he was "interfering in the Russia investigation".
The FBI is not for investigating presidents. The constitution delegated that to the Congress. The FBI is a mere staff of the president, not someone tasked with watching him.
That’s third world banana Republic crap.