Factual error: The underground station shown is not St. James Park, which would be 1 stop east on the District line. St. James Park has green and yellow tiles on the wall indicating District and Circle lines. The platform in the film has black and brown tiles, indicating Northern and Bakerloo lines, neither of which serve St. James Park.
Factual error: When flying to France to have talks with the French premier a C47/Dakota is shown in the background intimating that it was the plane he came in. The C47 did not enter service with the RAF until after this period of the film with Lend Lease.
Continuity mistake: When Churchill is delivering his first speech on May 13th, Neville Chamberlain places a handkerchief on his leg to use as a signal to his fellow MPs. During the speech you can see Chamberlain sitting a few places away from Churchill but the handkerchief is missing. Then, a short while later in the same scene, the handkerchief is back with Chamberlain's hand over it.
Factual error: Churchill is frequently shown drinking from Waterford Crystal initially in the first scene when he drinks whisky with breakfast. The ‘Lismore' style shown was not introduced until 1952.
Factual error: When George VI and Churchill are having lunch at Buckingham Palace there are servants in the room. In reality, servants were not present at their wartime lunches due to the often highly secret content of their conversations. Food and drinks were left in the room by Palace staff and the King and Churchill served themselves.
Factual error: While assessing Churchill's record as First Lord of the Admiralty, the loss of an aircraft carrier during the Norway campaign was mentioned. In fact, Glorious was lost on June 8 1940 - roughly a month after Churchill's appointment as PM. (00:16:05)
Factual error: As they are leaving the war rooms a car can be seen parking in the background. This car is an Austin A30 and these were not introduced until the mid 50's.