The third person narrator of "Dry September" doesn't delve into the inner minds of its characters, except in the case of Miss Minnie Cooper, and even then not too deeply. The narrator seems objective, meaning it doesn't pass judgment on the characters directly, but leaves this to the readers. Other than Minnie, the characters are revealed to us only through their actions and their words.
Still, the narrator is arranging things in specific ways, deciding what to tell and what not to tell. This is not a journalistic narrator reporting the facts, but a secretive, reserved narrator reporting some of the facts. The fact that gets reported most often is that nobody in Jefferson knows all the facts. The narrator knows what happened to Will after Henry jumps out of the car, but doesn't say. It knows what did or did not occur between Minnie Cooper and Will, but likewise, it isn't talking. We have our guesses as to these matters, but no definitive answers.
By never revealing whether or not Will raped or sexually harassed Minnie, and by never revealing what McLendon and company does to Will, the narrator places the reader in a similar position to the people of the town. Like the townspeople, we don't know the truth. As such, the narrator could be encouraging us to not be like the town, but rather to base our judgments on the information we actually have. The narrative voice might seem to be objective, but we can never forget that leaving out information is way of influencing thought and skewing interpretation. Regardless of what might or might not have happened between Will and Minnie, what McLendon and the other men do wrong in taking matters into their own hands. Through omission and objective narration, the story tries to get this basic idea through to the readers.