Other mistake: During the 'Little Black Dress' number, look carefully at Cosmo's plans for the dress, they read 'The Brad and Janet Show' as this was to be the original title of the film. It doesn't really fit for Shock Treatment because the show being planned is only Janet, Brad is locked in a cage.
Trivia: When Betty and Ollie are talking in their office (and Ralph and Macy come in), look carefully at the table all the way to the left. There's an issue of Time Magazine that says "Cult Classics," with a picture of The Rocky Horror Picture Show's famous red lips. (That film was the predecessor to Shock Treatment).