Directed by: Billy Wilder
Starring: Shirley MacLaine, Jack Lemmon, Fred MacMurray, Ray Walston
Continuity mistake: During the second round of drinks, the amount of ice left in the frozen daiquiri changes depending on the camera angle. It's poofy and opaque in the side view, and deflated and almost fully transparent in the tighter close-up on Shirley MacLaine, with an intermediate angle and state. (00:38:10)
Factual error: Jack Lemmon cooks spaghetti for Xmas dinner. On New Years Eve he picks up the tennis racket, through which he had poured the spaghetti, and one piece hangs limp from the racket. It would of course, have long dried and be hard as before cooking.
C.C. Baxter: The mirror... It's broken.
Fran Kubelik: Yes, I know. I like it that way. Makes me look the way I feel.
Trivia: To make the office appear larger than it was, the team used forced perspective - adult actors at the front, with child actors behind them, and tiny desks with wire-operated dolls at the back.