When Cathy first comes out of the bedroom and overhears Larry and Noelle planning her demise, she has on underpants beneath her nightgown. But when she runs outside into the rainstorm and her nightgown gets soaking wet you can plainly see she has on no underpants.
In a shot taken in Paris, during WW2 and German occupation, with a very large Nazi flag in the middle of the place, we can see, very far away, in the mist, the Montparnasse tower, which was built only in the early seventies.
In some scenes set in 1946, Larry is driving an MG TD roadster, a model which wasn't introduced until 1950.
The opening scene, which takes place in 1947, has Deneris traveling to the Greek prison on his yacht, to visit Noelle in her jail cell. The yacht has radar fixtures mounted on its roof that were not developed until the 1960s.
When Noelle insists that Larry fly her to Switzerland in Deneris's private plane in the middle of a snowstorm, the plane lands at night on a 1970's airport runway. Seen through the plane's windshield, the runway has pathfinder landing lights along its edges and strips of florescent landing lights down its center. (A 1947 airfield would have used large searchlights as landing lights.)
When Larry leaves Cathy in the caverns, one time when she yells out his name but her mouth is not moving.