Despite the boat exploding sometime in the morning, the police still manage to get all the pieces of wreckage and the bodies recovered from the sea, sorted, and laid out in the boathouse well before sunset the same day.
Anna (Diana Dors) stumbles and falls under the same gorse bushes at least twice during different scenes of her being hunted on the island.
When Joan Foster speaks about the tape recording to Sir Mark in the boathouse, where he is carrying out an autopsy on the dead trustees, Sir Mark is clearly sampling parts of an real dead octopus rather than a prop human organ.
At one point the ferry is shown going down a river to the sea. This scene looks to have been shot in Falmouth, Devon, some 500 miles south of the Scottish Isles.