The book leaves the question open on purpose. Bentinho does not hide that he chooses what he tells. From the very beginning he confesses that the project of the house failed. In chapter XIV, he cuts the scene of the wall because he wants to be spared. In chapter LIX, he says he prefers books that omit to those that are confused. In chapter LXXIX, he warns that what he tells about Dona Glória's hope is something he only later "presumed" to discover. It is this partial frankness that gives authority to the rest.
He also promises to tell his very essence, "all of it, the good and the evil," and in fact confesses the thought that, with his mother dead, he would finish the seminary, and the instant of "vertigo and sin" when he pressed the hand of Sancha, his friend's wife. But the book shows a difference in measure: he absolves in a few lines the desire he confesses to feel for his friend's wife, while he reads a look of Capitu's as evidence.
The reader may see in him someone who lies, someone sincerely deceived, or someone who needs a guilty party to explain his own life, and each reading changes the genre of the novel. What the text sustains is that everything arrives through him: the eyes of Capitu, the resemblance of Ezequiel and the photograph only acquire meaning because he interprets them after deciding.