Plot hole: Farley Granger meets a math professor on a train bound from New York to Washington, and is able to prove as much to the police. The professor got on in New York and got off in Wilmington, DE, while Granger boarded the train in the fictitious town of Metcalf, NJ, and rode on to Washington. Thus, they met between Metcalf and Wilmington. But the police say Granger could have boarded the train in Baltimore, by which time the professor would have gotten off and they never would have met.
Plot hole: Klaatu is shot and his body is lying in a prison cell. Gort leaves the flying saucer and walks all the way to the heavily guarded police station in downtown Washington DC. Gort is 8 feet tall and is a robot plus he uses his noisy death ray to create a hole in the police station to retrieve Klaatu's body and nobody noticed him? On top of that, he walks all the way back to the saucer unseen with a dead body. (01:22:36)Larry Koehn
Plot hole: When Hornblower arrives home from the Pacific, he meets his son, a baby in a cradle. He is given the Sutherland, sails to Spain, is captured and escapes, and returns to England a hero..all in under a year. However, upon arriving in Portsmouth to see the Admiral, he visits his son, now a child of 3 or 4.