Factual error: When Fleming salutes Cholmondeley and Montague, they return the compliment whilst not wearing their headdress. Members of the British armed forces never salute if they are not wearing a hat, instead they would stand to attention.
Factual error: In the nighttime hostage rescue scene, the rescue helicopter has its right and green navigation lights on, which are designed to show other aircraft where it is and which direction it is heading. This of course would not be the case while staging a clandestine operation in hostile territory.
Other mistake: Valeria put the teakettle on the gas burner right before JJ buzzed to come into the building. About a minute passed until JJ got inside and more than a minute passed until Valeria went to check on her child. Valeria never returned to the teakettle. More than enough time had passed for the teakettle to whistle that the water was boiling, but no sound came from the small adjacent kitchen. (00:17:02 - 00:19:17)
Factual error: At the end of the film, Hellfire Jack returns the toy soldier to the son of the late William Hawkins in 1917. Hawkins son is shown taking it upstairs and placing it in front of a photo of his father, in between two medals. These are the British War and Victory Medals - these did not exist until 1919, and in most cases were not even issued until the 1920's.