Although the story is told from the third person point of view (he, she, they, etc...), it is presented in such a way as to represent Mrs Foster's feelings more than her husband's. The reader "gets under her skin" and empathizes with her cause. However, her choice at the end of the story comes as a real surprise; the narrator catches the reader off guard at the 'funny smell' emanating from the elevator.(Many readers still don't "get it!")
Mrs Foster's pretention to not know about the morbid fate of her husband is very much akin to the "innocence" of another character, Mrs Maloney, in Dahl's short story "Lamb to the Slaughter." Both stories are told from the omniscient point of view (third person, all-knowing), with the women feigning ignorance about a crime they have committed. For this reason the narration looks as if is told from a limited vantage point, but it really isn't.