I think there is a lot of misunderstanding going around about what the intention of this film is. As a docudrama based on the autobiography of General Roméo Dallaire, and a companion to the 2005 documentary of the same title, it is meant to portray his emotional reaction to his experiences rather than to be focused on the details of Rwandan genocide.
As such, I feel it succeeds as his mounting frustrations are palpable to the viewer but do not stray into the territory of melodrama. It may be a bit hokey to watch the depictions of phantoms from his past having conversations with him in the psychiatrist's office for some, but I accept the technique as furthering the goal I stated in the interest of necessary brevity.
I am familiar with Roy Dupuis from the television series The Last Chapter, which starred Michael Ironside and was about biker gangs. Here I feel he does a good job of portraying the man, but is somewhat stiff at times and perhaps doesn't reach the emotional center of his subject.
Overall I'd say the film underscores how powerful the documentary is, with its success at portraying the same issues with depth and aplomb, and if a viewer were to choose one format over the other it would be better to watch the real man speak.