Continuity mistake: When Gus March-Phillips is being recruited, Gus helps himself to whisky then grabs some cigars from a cigar box. The cigar box is easily identifiable as a Fuente Fuente Opus X brand, made by Arturo Fuente. Opus X cigars were first produced in November 1995.
Factual error: Ian Fleming explains to March-Phillipps that the U-boats need "fuel and torpedoes, but they also need carbon dioxide filters, for oxygen." U-boats didn't have CO2 filters. They had the air on board when they dived, which, along with the batteries supplying the electric motors they used when underwater, limited the time they could remain submerged. There were several instances of U-boats being forced to surface after long periods of being depth charged; their air supply had been exhausted. (00:12:00)
