Of course, that wasn”t the title all along. In 2008, months after he won the Academy Award for his harrowing torture study “Taxi to the Dark Side,” Gibney began work on “The Road Back,” a film intended to be a mostly admiring portrait of the seven-time Tour de France champion as he prepared for a comeback from retirement and an eighth victory in cycling”s greatest race. Needless to say, things didn”t quite pan out that way. Armstrong finished the 2009 Tour a respectable but personally disappointing third, but that was the least of his troubles, as the doping allegations that he had strenuously denied throughout his career became ever more compelling and, in time, impossible to dismiss.

That left Gibney, to all intents and purposes, high and dry: the New Yorker had a heap of raw material for a celebratory film about a figure whom, it appeared, was hardly worthy of celebration. Gibney shelved the project, but didn”t abandon it. As the Armstrong case grew more complicated, and its consequences more severe, the director saw he had the makings of a rather more unusual film about the fallen idol – one that could use its own interrupted development to reveal how Armstrong pulled the wool over the world”s eyes, Gibney”s included. As such, it requires the filmmaker to play both puppeteer and patsy, breaking form by foregrounding his own relationship to his subject – “The Armstrong Lie” may be as deliberate and insightful a work as we”ve come to expect from Gibney, but it”s colored by his sense of personal disappointment and professional pique.

The irony, explains Gibney, is that this unforeseen turn of events wound up making for a film that was, in a sense, more typical for a filmmaker accustomed to taking a tough line on tough subjects. “A feel-good story would have been unusual for me, and I was actually looking forward to that,” he laughs over the phone from New York. “So in a funny way, when the shift came about, it came back to more familiar territory for me.”

Still, he”s quick to point out that even at the beginning of the process, he never had “a Disney film” in mind. “Even in the first film, I dealt with the allegations of doping,” he says. “The title ‘The Road Back” had a double meaning, referring to both the comeback and the road back into the past. I liked the idea of a redemption story: the idea of a guy coming back at an ‘advanced age,” and doing it clean, as if to prove that he was great no matter what. That was an interesting quest to observe, as long as I could deal with the allegations – which I thought he was confronting. I thought that was one of the reasons for his comeback: that, from his point of view, it didn”t matter if he”d doped in the past.”

While that essential thesis for the first film turned out to be entirely false, that didn”t mean Gibney couldn”t use it. “It wouldn”t have done any good to start from scratch,” he explains. “I had to make room for the film I”d already done – that”s part of the unique contribution I could make to the story of Armstrong. I had all this wonderful footage that no one else had, that cast a completely different light on his story. I just had to integrate that into a more familiar investigation.”

It was bridging those two objectives that led Gibney into taking a more first-person approach than he usually does in his films: “It seemed to me by then that I was part of the story, inside and out. So by portraying my own journey, I could both be critical of my role in the promo job and create a clearer back-and-forth structure. By making myself a character, I could make narrative jumps that I wouldn”t have been able to do otherwise.”

Though Gibney is accustomed to narrating his own films, he doesn”t mind describing his increased personal presence in this one as “a bit uncomfortable.” “I”ve tried it in other films and always rejected it, because it felt too navel-gazing and self-regarding,” he says. “In this case, however, there seemed a greater point to it. I was part of the problem as well as part of the solution-the admiring fan-which made a lot of sense for the narrative structure.”

A keen sports fan, Gibney nonetheless admits that he had little knowledge of Armstrong when he first came to the project, having been interviewed by producer Frank Marshall as one of several potential directors for an Armstrong film. What was the attraction? “My pitch to them was that I was interested in will. Both the motivational side of that-the comeback from cancer, the will to win-but also the dark side. I saw Armstrong as a combo of [Major League baseball player] Jack Armstrong and Daniel Day-Lewis in ‘There Will Be Blood.” There was a darkness to him: he told me his slogan was ‘Win-lose, live-die.” Most of us don”t think of losing as akin to dying, and that”s the part of him I was intrigued by. Part of him was inspiring, and yet part of him represented this very American win-at-all-costs ethic.”

That fascination endures, Gibney insists, despite Armstrong”s downfall. He explains: “I”m not one of those who, having discovered that he cheated, had to believe that he was an incompetent, untalented athlete who just took drugs and sat on his bike seat as the drugs took hold and pedalled him up the mountain. I think he”s a great athlete: he clearly had physical gifts, and a will to win. And with many great athletes, the thing for which we most admire them is often something rather dark – that drive can come with a degree of cruelty. You have to want to crush your opponent. Michael Jordan had that. Serena Williams has that. It”s beautiful from afar, but far from beautiful.”

The timeline of Gibney”s initial film ended with Armstrong”s dismal performance in the 2010 Tour de France, when he finished in 23rd place – an omen to the greater descent that lay immediately ahead. But even as the film was fully mixed and edited, with narration in place from Matt Damon, the director knew that it was “insufficient for the time we were facing,” with federal and criminal investigations into Armstrong”s offenses looming.

“It was a pretty good film,” he says, “but what if there was something bigger going on here? The story was becoming about more than athletics: it was about what kind of human being he is. The other film was about human beings” hubris and power. ‘The Armstrong Lie” is a different film, and I do think a better one.”

As Gibney reconceived the film, he made a concerted effort to keep Armstrong informed and involved: the cyclist agreed to provide an on-camera statement for the film earlier this year, after his much-vaunted confessional interview with Oprah Winfrey – a coup Gibney had hoped would be his.

“Lance had briefly promised me that my film would be the one in which he finally came clean – another promise he broke,” he says with a rueful chuckle. “I”d had conversations with him on camera and off, and I kept hoping he would understand that his abuse of power was really the story here. But the purpose of including his statement at the end, which basically amounted to a plea that he be recognized as the winner of the Tour de France, wasn”t to present Lance”s argument in a literal sense. It was to signal my own disappointment that, at the end of the day, this is what he”s still focused on, rather than something bigger.”

That “something bigger”-the arrogant betrayal of public trust-provides a neat thematic link between “The Armstrong Lie” and Gibney”s other hot-button documentary of 2013, his Julian Assange study “We Steal Secrets: The Story of WikiLeaks.” Gibney is excited by the connection, but admits he couldn”t have calculated it: “By the time I started ‘We Steal Secrets,” I”d put ‘The Armstrong Lie” aside, so I didn”t know exactly how it was going to play out. But an eerie symmetry emerged: there are key similarities in the way those stories are seen, and the way their central characters judge themselves and curate their own myths.”

It was while interviewing data journalist James Ball for “We Steal Secrets” that Gibney stumbled upon the theme that binds not just those two films, but “Mea Maxima Culpa: Silence in the House of God,” his Emmy-winning 2012 documentary about sexual abuse in the Catholic Church. “Ball idly referred to the concept of ‘noble cause corruption,” which I then studied a great deal,” he says. “That”s the psychological mechanism of people who allow themselves to do bad because they believe they”re serving a higher cause. That became very interesting to me, and informed all three narratives.”

Though people often speak of narrative cinema in opposition to documentaries, Gibney repeatedly refers to his films as “narratives,” and his subjects as “characters.” “It”s kind of a weird exercise you go through,” he explains, “because you”re speaking to these people as you would any other human being – you”re not thinking of them as characters. But inevitably, in the cutting room, that”s what they become, because you have to place them in a narrative framework. That”s what editing non-fiction film is all about: constructing a narrative out of real events, and making sense of them. So you end up seeing the role a person is playing as you”re putting the film together.”

One of the most prolific directors in the business, Gibney is currently finishing work on a film about African music icon Fela Kuti – a project that has the inspirational elements he”d initially hoped to tackle when taking on Lance Armstrong”s story. On top of his own workload, meanwhile, the active Academy member has been taking time to view a number of the films competing for this year”s Best Documentary Feature Oscar. “We Steal Secrets” and “The Armstrong Lie” are two of the 150-plus films that have been submitted – a record number. Is he managing to see his share?

“It”s hard to know what ‘my share” is!” he says. “We have a de facto system now, whereby each member of our branch tacitly agrees to see a certain number of films that are prescribed, so we can ensure every submitted film is seen by a certain number of voters. And if one that has previous been unheralded really pops out, we can begin spreading the word. I”ve seen my prescribed list, and I”ve seen a bunch of others, but can I see 150? No.”

Still, from the sample he”s seen, Gibney is upbeat about the quality of competition this year. In our interview last year, he waxed lyrical about Sarah Polley”s deft, moving family memoir “Stories We Tell,” and remains just as enthused; “Gideon”s Army” and Errol Morris” “The Unknown Known” are among the other titles that come in for praise. “What amazes me is what a dynamic era for this medium,” he says. “Documentaries come in all shapes and sizes now, and that eclecticism is what is so inspiring.”