Throughout the novel, Hastings and Poirot act as foils to one another, especially because they often react differently to new evidence. Hastings is impulsive, rash, and eager to believe what he sees, often dismissing evidence that contradicts whatever he instinctively believes. Poirot, on the other hand, is cool, logical, and dedicated to turning over every possible stone. In Chapter 7, Poirot’s insistence on patience and careful consideration of all evidence leads him to make the following paradoxical statement regarding the proof of Alfred Inglethorp’s guilt:
“Yes, yes, too conclusive,” continued Poirot, almost to himself. “Real evidence is usually vague and unsatisfactory. It has to be examined—sifted. But here the whole thing is cut and dried. No, my friend, this evidence has been very cleverly manufactured—so cleverly that it has defeated its own ends.”
While Hastings is all too ready to accept Mr. Inglethorp’s constructed narrative as the whole truth, Poirot’s years of professional experience hold him back from making the same conclusion. Poirot says that the evidence pointing towards Alfred is "too conclusive," which paradoxically leads the detective to suspect something is amiss with the situation. Thus, the too-perfect alignment of evidence ends up backfiring on Alfred Inglethorp’s plans by alerting Poirot to the fact that his suspect is hiding other secrets.
