In the ballroom scene, where Jack Lemmon is playing the role of Crown Prince Frederick, he begins dancing with a fetching young woman. But in an cut or two later, he's visible behind Leslie, and he's dancing with a guy in uniform. Then dancing again with the original woman in subsequent cuts. I had never noticed that. Great movie--basically for Lemmon and Falk. Anybody suddenly notice something in a movie they had seen many times?
I was watching the same movie tonight. I noticed during the beginning of the pie fight scene you could hear the sound of a still camera taking photos. Probably for publicity stills.
I don't remember that, either (but you're apparently not the only one to have spotted it.) I'll have to look out for it next time. Also for Natalie Wood, Larry Storch, the swordfight between Tony Curtis and Ross Martin ("So, until another day, Mr. Leslie, please excuse me - I have a boat waiting”), pie fight, etc., etc. It's one of my favorites.