Agatha Christie insults Harriet Vane. The nerve!
(I also think she might have missed the point of the maggots-and-Gorgonzola description - it's meant to imply, surely, that he looks the perfect silly ass about town, and his face looks accordingly right with the top hat, rather than implying anything maggot-like about his appearance.)
The Wikipedia* entry for Lord Peter Wimsey includes one section that has always puzzled me:
At the conclusion of Strong Poison, Inspector Parker asks "What would one naturally do if one found one's water-bottle empty?" (a point of crucial importance in solving the book's mystery). Wimsey promptly answers "Ring the bell." Whereupon Miss Murchison, the indefatigable investigator employed by Wimsey for much of this book, comments "Or, if one wasn't accustomed to be waited on, one might use the water from the bedroom jug."
But the water jug was a red herring - it was the omelette Wot Dun It. Was this a "point of crucial importance", and have I just missed it?
*Firefox's spellcheck suggests "Windpipe" for this word; it seems surprising that it hasn't been added to the dictionary. That said, both "Firefox" and "spellcheck" are apparently alien words, so viewed in that light it's a bit less odd.