Sir Ranulph Fiennes, an English adventurer, polar explorer and former S.A.S. man is the author of The Feather Men, the novel on which this film is adapted. Although he has often claimed the novel was a true story, the families of the real dead S.A.S. men named in the novel who died on S.A.S. exercises, and the S.A.S. themselves publicly attacked it as sick exploitation and complete fiction. The S.A.S. even went on the record to disown both Fiennes and the book, with Lieutenant Colonel Ian Smith telling the Daily Mail "It was utter bullshit", the figment of a fertile imagination. What was really upsetting, was that it was making a story out of a tragedy." Maggie Denaro, the widow of one of the dead S.A.S. men said of Fiennes, "It's time he grew up. He's made his money out of the book. He should come clean. When the book came out saying Mike had been murdered, we knew it wasn't true. But that didn't stop our children from being upset when other people believed it." Although Fiennes claims he sent a manuscript of the book to the S.A.S. and the families of the dead men, who gave their approval, they have all unequivocally denied his claim.
The controversy over whether the story is true or not has as many twists as the plot itself. As mentioned above, all the families and the S.A.S. denied they had been consulted or involved in any way with the book. However, an article the Daily Mail Online was forced to include an amendment when the widow of Major Mike Kealy admitted she had read and approved of every page that related to her husband.
This film is in no way a remake of Sam Peckinpah's film. Peckinpah's film is entitled The Killer Elite (1975).
In the scene where the SAS are going on training in the Brecon Beacons, they are seen wearing the incorrect uniform for the period. In 1981 the British Army wore 1968 pattern Smock, Combat but here they are seen wearing P84 smocks which did not start being rolled out until circa 1985