The biggest irony is that, all through the story, the two men in the story are making all sorts of assupmtions, inferences, criticism, judging, blaming, and labeling while their wives, whom they have specifically told to stay away from making assumptions, inferences, criticism, etc are the ones finding out every single clue that is available to resolve exactly what happened in the household that night.
Moreover, the women are able to put together through what the men deem to be "trifles" a perfect scenario of the crime complete with motif, cause, effects, and results. All this, they did by superficially looking at the scene and making connections. The men? Clueless, and one of them was an investigator! They made it all look like it was the case of a very bad wife being even worse. Little did they know that they had a case of wild spousal abuse in their hands, but they were too fanatic of their contempt against women to actually put the two together.