By its producer's admission the film is a simplified and dramatised version of the story, and sharp-eyed viewers will catch sight of the Ladybower Reservoir which – although the dam was being completed in 1943 - did not actually hold much water when 617 Squadron were training. Furthermore, the tower of Derwent Church was demolished in 1947, so the landmark that was so well-known to the original crews did not appear in the film. Also at the end of the film, long after Guy's dog was dead and buried, Richard Todd is talking to Michael Redgrave (Gibson, Wallis) a black Labrador can be seen running around the airfield, over Todd's left shoulder. 'The ghost of Guy's dog lived on!