Other mistake: There are 20 divers counted onto the boat. They all head into the water in 2s, but somehow there is 1 person left without a diving buddy.
Other mistake: The couple are shown travelling on an American Eagle prop plane in the islands, but on-board you see them sitting together with another lady sitting on the left of Susan. The prop planes don't seat 3 together. This shot must have been filmed across the aisle on a larger jet. (00:03:25)
Answer: The film was inspired by an incident at St Crispin's Reef, a dive site on the Great Barrier Reef in 1998, when Tom and Eileen Lonergan was left behind by their diving boat after an error was made during the headcount. They were never seen again. More information can be found at http://outside.away.com/outside/features/200310/200310_mysteries_2.html.
Tailkinker ★