Plot hole: Sergeant Howie is expected to report back to the mainland on the same day he left, and since he took a valuable aircraft with him on his trip it is inconceivable that his superior officers would not come looking for him if he didn't show up. First they would try contacting him on his radio and not receiving a reply they'd send out a search party, and they would do so within twenty four hours. Missing police officers are taken very, very seriously indeed.
Plot hole: Edward Lionheart severs the head of theater critic Horace Sprout while Sprout and his wife are asleep. (Lionheart gave them both a knockout injection). Sprout's wife (and his maid)discover the severed head in the morning, and both scream and faint. But in the next scene, critic Perry Devlin retrieves his morning newspaper and then reaches for his bottle of milk, only to find Sprout's head perched on the milk bottle. How did the head get from Sprout's house to Devlin's place?