Analysis by Gregory Krieg, CNN

(CNN) -- In former FBI director James Comey's telling, he and President Donald Trump are perfect foils. He recalls their White House meetings in tense, cinematic terms -- the upright G-man, bound to "a higher loyalty," facing off with a glorified mafia boss in ruthless pursuit of fealty and favors.

"He had impressively coifed hair, it looks to be all his," Comey recounted in his Sunday night interview, before commenting on Trump's "slightly orange" visage, the length of his tie ("too long") and hand size ("average"). The President asked for loyalty and, at a subsequent sitdown, expressed his hope that Comey would go easy on former national security adviser Michael Flynn, who has since pleaded guilty to lying to the FBI.

For someone who says he never wanted to write a memoir, Comey exhibits rare talent as a storyteller. His book is short and, whether one finds it compelling, self-serving or pretentious -- those, with some overlap, seem to be the most popular takeaways -- it never drags. The descriptions of his exchanges with Trump, as first documented in contemporaneous memos and then leaked to the press, are consistent. But the sum effect can be oddly unsatisfying. Comey's observations, hints and innuendo never quite pull together to form a clear picture of the President or the precise extent of his alleged misconduct.

Instead, we get a lot of: "It's possible."

Comey fell back on the phrase repeatedly during his conversation with ABC's George Stephanopoulos.

When asked if he believed Trump, who in Comey's account tripped over his tie denying those most salacious details of the Steele dossier, Comey said, "It's possible, but I don't know."

Asked if he thought "the Russians have something on Donald Trump," Comey first responded: "I think it's possible. I don't know. These are more words I never thought I'd utter about a president of the United States, but it's possible."

Pressed by Stephanopoulos, he'd utter them again a few seconds later: "It always struck me and still strikes me as unlikely and I woulda been able to say with high confidence about any other president I dealt with, but I can't. It's possible."

Comey's flair for the dramatic has already been discussed and examined at some length. Trump once derided him as a "showboat," which -- even allowing for the source's obvious bad faith -- is hard to deny. Comey has conceded that his "ego" has a habit of leading him astray. (His relative openness to that sort of introspection sets him apart from the President.)

The unpredictability, talent for stringing out a juicy story, and frequent diversions from political "norms" are the most common threads between the two men. Again, Comey seems to have more care for how his arguments and actions land, but there is a recurring sense in his recollections that, in any given moment, he has a special mandate to act.

From what unique authority that stems is, if not always unclear, inconsistent and sometimes dubious.

Questioned by NPR's Steve Inskeep and Carrie Johnson about his decision, in July 2016, to publicly announce that the FBI would not recommend criminal charges against Hillary Clinton for her handling of classified documents and sensitive information, Comey argues that his break with protocol was meant "to protect" the FBI and Justice Department. The latter, in his mind, had been tainted by Attorney General Loretta Lynch's perceived proximity to the Clinton camp.

"In the ordinary case," Comey said, "we would most likely in writing prepare some sort of summary of what our investigation had determined and then send it over to the Justice Department, and they would in the ordinary case either say nothing, which is the most common case, or at most issue a letter to the target saying, or the subject saying it's over, or some minimal statement about it."

But in Comey's telling, there was nothing ordinary about his conundrum. In fact, it was so abnormal and consuming as to be biblical in nature.

"I saw this as a 500-year flood," he told NPR. "And so where's the manual? What do I do?"

What Comey did was step outside the accepted borders of his position and, in what he again describes as an effort to preserve "the public trust" in the FBI, and the investigation more generally, effectively cut out his bosses at the Justice Department.

Had the actual decision not cut against his interests, it was a move Trump likely would have applauded. When Comey decided, months later, to send a letter to Congress -- 11 days before the election -- with news that the FBI had "learned of the existence of (previously undiscovered) emails that appear to be pertinent to the investigation," the future president did just that.

"It took guts for Director Comey to make the move that he made in light of the kind of opposition he had where they're trying to protect her from criminal prosecution," Trump said on the trail. "You know that. It took a lot of guts."

A little more than six months later, Trump fired Comey, paving the way for the appointment of the special counsel and a new role — perhaps the one, after all these years, that fits him best -- for the man Stephanopoulos called "the Zelig of modern law enforcement."