"Rod Rosenstein, the deputy attorney general tasked with drafting a memo to explain the removal Tuesday of FBI Director James Comey, threatened to resign after he was painted by the Trump administration as the mind behind the firing, according to The Washington Post.

The Post, citing an anonymous source close to the White House, said Rosenstein felt like he was “cast as the prime mover of the decision to fire Comey,” when in fact he was asked by administration officials to draft the memo after President Donald Trump had already decided to fire the FBI director...

Trump’s formal letter dismissing Comey pointed specifically to Rosenstein’s memo and ultimately said the FBI director was “not able to effectively lead the bureau.” Vice President Mike Pence, speaking to CNN, also said the decision was based on Rosenstein’s memo."
Deputy Attorney General Reportedly Threatened To Quit Over Comey Backlash http://www.huffingtonpost.com/entry/rod-rosenstein-quit-comey_us_5913eb36e4b066b42170fe7b