Revealing mistake: During the car chase, the dump truck tailgate is closed when dumping sand onto the Cadillac. With the tailgate open, the sand would not have filled the interior of the convertible.
Visible crew/equipment: There is a boom mic visible when Eunice is arguing with the badge lady over her identity.
Continuity mistake: When the reporter leaves the airport terminal with the document bag he gets into a Yellow Cab number 710, with no billboard on the back. When he exits it is still 710, but there is a billboard on the back of the cab.
Continuity mistake: During the chase scene the sun visors on the stolen VolksWagon are visible in some scenes and apparently removed in others.
Continuity mistake: During the chase scene the sheet of "glass" carried by the workers is too flexible, and is probably a sheet of plastic. The sheet that breaks is not the same sheet that is set down on the sidewalk; the (white) worker's upper suction cup is on the ladder side, but when the sheet is broken it is on the opposite side.
Audio problem: About 10 minutes into the movie, Howard and Eunice are standing at the head of the hotel's escalator listening to Judy define the word "propriety" as she descends; instead of diminishing in volume as it ought to, the volume in this speech stays the same and even increases a little right at the end.
Continuity mistake: When Judy Maxwell approaches the front desk near the start of the movie, signs above where the room keys are kept indicate that the hotel only has 19 floors, with most of the film's action taking place on the 17th. However, when Howard gets in the elevator the next morning (after the visit from Kaltenborn), the elevator starts at floor 31, going up to floor 33 or so before coming out on the unfinished roof restaurant.