President Donald Trump's decision to fire former FBI director James Comey in May 2017 was later described as perhaps the "biggest mistake in modern political history" by Mr Trump's then advisor Steve Bannon.
If Mr Trump's presidency is brought down by the Special Counsel investigation that Mr Comey's ouster triggered, that assessment will be hard to argue with.
At this point, it is still a matter of legal opinion whether the President's alleged request that Mr Comey drop the FBI's investigation into former National Security Advisor Michael Flynn, amounts to obstruction of justice or not.
Mr Flynn has since admitted to lying to the bureau about meetings with Russian officials. He copped a plea and is now cooperating with Special Counsel Robert Mueller, who has bigger fish to fry.
But on that crucial obstruction question, Mr Comey — in his first interview since his sacking — told ABC America's George Stephanopoulos: "Possibly. I mean, it's certainly some evidence of obstruction of justice. It would depend and — and I'm just a witness in this case, not the investigator or prosecutor, it would depend upon other things that reflected on his intent."
Meanwhile, as for what the President might have been seeking to cover up, Mr Comey says "it's possible" Mr Trump has been compromised by the Russians, although he still thinks it's unlikely.
However, that Mr Comey considers it's even possible, is itself pretty remarkable. The President of the United States may be being blackmailed by a hostile foreign power. And given Mr Comey is one of Mr Mueller's star witnesses, it's unsurprising he's leaving those final determinations to others.
Trump's 'average-sized hands'
The interview, to coincide with the release of Mr Comey's memoir, did provide plenty to entertain.
He talked about his first meeting with President-elect Donald Trump in January 2017 — noting the elaborately coiffed hair, which Mr Comey says "looks to be all his. I confess I stared at it pretty closely and my reaction was it must take a lot of time in the morning".
So he (and perhaps he alone) thinks Mr Trump's hair is real.
Mr Comey continued: "His tie was too long as it always is … he looked slightly orange up close with small white half-moons under his eyes, which I assume are from tanning goggles."
As for Mr Trump's hands, "as I shook his hand I made a note to check the size and it seemed like he had average-sized hands," he told Stephanopoulos.
But overall, Mr Comey's account of the meetings he had with President Trump, including an awkward private dinner, was not that new.
He gave similar details in leaked memos following his sacking, including Mr Trump's alleged demand for Mr Comey to pledge his personal loyalty, and in congressional testimony.
Damned if he did, damned if he didn't
The hour-long interview, cut from a reported five-hour conversation, had begun on more uncomfortable ground for Mr Comey. Many believe his reopening of the FBI's inquiry into Hillary Clinton's use of a private email server as Secretary of State barely a week before the election, while making no mention of the active inquiry into Mr Trump and Russia, swung the election to Mr Trump.
Before his sacking by President Trump, Mr Comey said the thought he had affected the outcome made him "mildly nauseous". That comment in turn made Mr Trump more than mildly irate and he soon gave the FBI director his marching orders — via TV.
Mr Comey now says in the weeks leading up to the 2016 election he, like everyone else, were working on the assumption that Mrs Clinton would win, and that by not announcing the reopened investigation so close to election day, he could delegitimise the result — which was Russia's ultimate aim.
His ongoing queasiness with the situation he found himself in remains evident, "Speaking is really bad; concealing is catastrophic. If you conceal the fact that you have restarted the Hillary Clinton email investigation, not in some silly way but in a very, very important way that may lead to a different conclusion, what will happen to the institutions of justice when that comes out?"
So, damned if you do, more damned if you don't, but Mr Comey also says he would do nothing differently given his time over — his self-belief seems pretty unshakable.
'Everybody hated me'
His self-pity is similarly enduring,
Mr Comey says the days leading up to the 2016 election "sucked".
"I felt like I was totally alone, that everybody hated me. And that there wasn't a way out because it really was the right thing to do".
In the end, we are presented with a man who seeks to hold the moral high ground and clearly wanted to stay out of politics, instead being dragged into the most extraordinary period in American politics since Watergate.
You can well see why this man, who at times seems like a fretful hand-wringing goody-two-shoes and who is also possessed with sanctimonious self-belief, also drives plenty of Democrats to distraction as well as President Trump.
'Morally unfit to be president'
But Mr Comey's final judgement of Mr Trump was expressed in those moral terms, and was devastating.
Stephanopoulos asked him whether Mr Trump is fit to be President of the United States.
"I don't think he's medically unfit to be president. I think he's morally unfit to be president," Mr Comey replied.
Mr Trump's moral equivalence following the racist violence in Charlottesville. Mr Trump talks about and treats women like pieces of meat. Mr Trump lies constantly about matters big and small.
"Our President must embody respect and adhere to the values that are at the core of this country. The most important being truth. This President is not able to do that. He is morally unfit to be president," Mr Comey said.
So, beyond obstruction of justice, the boasts of pussy-grabbing, or even a possible pee-pee tape, Mr Comey simply believes Donald Trump's essential nature makes him unsuitable to be Commander in Chief.
Mr Trump tweeted about 12 hours before the interview went to air, "Slippery James Comey, a man who always ends up badly and out of whack (he is not smart!), will go down as the WORST FBI Director in history, by far!"
All rather ironic then that probably more than anyone else, James Comey made Donald Trump President of the United States.