During the couple's nocturnal walk through London streets, the same backgrounds are passed twice in a single shot.
When David goes to console Pat, in one shot she has her hands down with a cigarette in her right hand. In the next shot, her arms are resting on her elbows with her hands clasped in front of her face.
When the vicar is reading the names and hometowns of the dead US aircrew he says that one of the fliers is from "Vermont, Maine". These are, of course, separate states.
Early in the movie, Corp. Patricia tells Major David that an officer had just arrived on a DC-3. She should have referred to it by it's military designation of C-47.