Style and Technique (Masterplots II: Short Story Series, Revised Edition)
The dominant technique of this story is that of ironic reversal. Not only does the plot contain reversals that challenge the surface meaning of the story, but also the characters, with their sometimes opposed, sometimes parallel visions of the world, establish expectations that are ironically reversed by the end of the story. The style intentionally directs the reader to think in terms of opposition: hunter versus hunted, strong versus weak, man versus animal, reason versus instinct, civilization versus brutality. However, these obviously opposed pairings disguise a greater complexity; the world is not really arranged so neatly. To be successful, the hunter must imitate the hunted, the man must act the animal, civilization must disguise its brutality.
The final irony, that Rainsford conquers a murderer by killing him, is a last trick on the reader, who has been led to believe that one of the values represented by half of each set of paired opposites is better than the other. No such certainty is possible in a story designed to challenge the conventional understanding of civilized behavior.