Continuity mistake: Right at the end, the insurance man gives Charlotte Jewel Mayhew's letter and in the next shot of him, his hands are empty. But in the following shot he's holding the letter again.
Other mistake: Subtitle (English) appears to be incorrect: "He is setting the scions of criminal investigations back 1000 years" should be "He is setting the science of criminal investigations back 1000 years." "Scions" is a description of the branches of a tree. (01:11:00)
Revealing mistake: When Marnie is dreaming, watch her window. The curtains move as if there is wind, but the window is closed.
Factual error: The movie shows a 'jet' aircraft belonging to 'consolidated airlines'. The so called airplane is a laugh. It has two jet engines attached to the horizontal stabilizers. The landing gear appear to be bolted to the wings. During the movie this plane crashes and the engines are moved to a terminal to be examined. They are too small to be real engines. During the course of examining the engines, they are run inside the terminal building. One of the investigators stands 10 feet behind the jet intake and is not sucked inside. The cockpit is not even close to what one would find in a jet airplane.
Other mistake: There were no gorgons named Megara. The three that existed were Medusa, Euryale, and Stheno.