The Rosenstein Angle
It's as bad as it gets when the boss ducks responsibility for the decisions he makes - when the boss is POTUS, it's worse than as-bad-as-it-gets.
We have a "president" telling us that firing Comey was somebody else's idea, and he was only acting at the suggestion of a subordinate.
"It was Reinhard Heydrich's idea to kill all the Jews - I was just following the recommendations of a trusted adviser."
And given what we've always known about 45*'s mastery at finding and exploiting the SmarmSpace, we have no reason to be surprised at this. It's what he does.