Comey had claimed that Trump had asked him to back off:
WASHINGTON (AP) — A memo detailing President Donald Trump’s request to shut down an FBI investigation of his ousted national security adviser is a powerful piece of evidence that could be used to build an obstruction of justice case against him.
But criminal charges of interfering with an investigation are difficult in ordinary circumstances, several former federal prosecutors cautioned Wednesday. And it’s an open question whether a sitting president can even face criminal charges, or whether attempts to hold him accountable for wrongdoing can only proceed through impeachment.
The White House has denied fired FBI Director James Comey’s account of a conversation he had with Trump in February, recorded in a memo seen by Comey associates. Still, to a prosecutor building an obstruction of justice case, the facts are compelling.
First, Comey says the president asked for his loyalty. Then he asked Comey to back off the FBI’s investigation of former National Security Adviser Michael Flynn, according to Comey’s memo. Then Trump fired Comey, declaring in a television interview that it was at least partly because he was bothered by the FBI’s probe of potential coordination between Russia and his presidential campaign.
It wouldn’t surprise me to find that Comey has some kind of hair-splitting legalism to prove that he’s not contradicting himself, he’s just being nuanced.