In this scene, Martin has concluded a scene as the missionary Clarence Ussher and the director (Charles Azanavour) gives him some brief correction. Rouben - the screenwriter (played by Eric Bogosian) steps in with an impassioned plea as to how Martin should play the scene and is put swiftly down by Martin who tells him "to back the fuck off!"
In his commentary Atom Egoyan explains that the scene was meant to show that the movie wasn't quite working out, but he cut the scene because it was a kind of "inside" joke - the sort of thing that happens so often on a movie set. It also looks with affection at the screenwriter and his place in the hierarchy of filmmaking.
Most of Atom Egoyan's comments were on Bruce's character, but he did refer to him often in the commentary and always in a complimentary way, as would be expected from these two collaborators. It is interesting to note that while Atom referred to Clarence Ussher as Ussher, he referred to Martin Harcourt as Bruce Greenwood:
In the first scene where Bruce appears, he simply says "The actor played by Bruce Greenwood.....I love the humor of this interchange with Rouben...."
In the second scene where we see Ussher in his mission, Egoyan says:
"Suddenly we see Bruce transformed into Clarence Ussher in a scene quoted from his book - "
He talks a bit about the scene cut from the film and how Rouben confronts Bruce and is told he's already done his research and doesn't need his help
Of another scene with Ussher: "We have this heroic image of Ussher - slightly puffed up and kitchy - overdone."
"This encouter of Ussher and JedVet Bey - He's a REALLY heroic figure. Bruce was able to really capture his indignation. Bruce, here - it's that incredible movie moment."
"Here we have a remarkable monologue from Bruce Greenwood. One of the most remarkable moments in the film. Is this Clarence Ussher? Or is this Bruce as Clarence Ussher? It's as though Bruce is trying to justify - And what right does Ani have to destroy it? Who has the moral authority to tell the story?"
At the premiere, when Bruce as Martin is being interviewed by a journalist, Egoyan says: "I love this moment where Bruce is being interviewed and says 'You have to believe in it' and then gets distracted and waves to somebody in the crowd. In the end, it was just a role he created."