Revealing mistake: When the UFO makes the huge flash that knocks everyone in the cemetery down, one of the police officers kicks a tombstone as he falls and it wobbles back and forth. (00:13:35)
Continuity mistake: It is supposed to be night when Joe slips out of the hotel, but a daytime sky is visible.
Factual error: The movie is set in Cardiff but the Transporter Bridge seen at the beginning of the film is really in Newport.
Other mistake: When Anne and Peter are looking at the stars, Anne points to a star and Peter knows what star she's pointing to. It is impossible to point to a star and have someone else know exactly what star you're pointing to. Try it.
Other mistake: A police officer fires two shots, hitting a bank robber in the back. The "bullets" do not make holes in the robber's coat. All they do is create two tiny puffs of dust.