The parachute harness goes from a simple backpack to a fully-rigged modern-style jump pack, complete with crotch straps.
Oxford tells his team they're starting the attack on the elevator at dawn, but the lighting is consistent with it beginning much later in the day, mid-morning at the earliest.
Conrad's arms change position from being crossed to apart between shots.
On the boat when the general is looking over the dead reports, he puts down the paper with his right hand and is still holding a page in his left.
But in the next scene he is holding the folder with his right hand and is pointing on the page with his left.
But in the next scene he is holding the folder with his right hand and is pointing on the page with his left.
There is a brief flashback showing the death of Tsar Nicholas and his family and while the scene has been painstakingly reconstructed down to the wallpaper of the basement, the family is shown being quickly killed with a single discharge of what appears to be a machine pistol by one person pretending to be a photographer. The real execution was far messier and cruel.
When Orland Oxford lands his biplane in front of his home, the screeching sound of the plane's wheels touching down can be heard even though the plane is landing on grass.
The Duke of Oxford tells his son, Conrad, that King George V, Czar Nicholas II, and Kaiser Wilhelm were all cousins and that their grandmother was Queen Victoria. Although both George and Wilhelm were first cousins and grandsons of Victoria, and Nicholas was George's first cousin, he was not Victoria's grandson. He and George were first cousins through their mothers, who were not Victoria's children.
Mata Hari's real name was Margaretha Geertruida Zelle. Her stage name Mata Hari means "sun" in Indonesian and is not a first name and surname. She would not have been addressed as Mata.
The exterior shots of the Kaiser's castle are actually Neuschwanstein Castle, which is in Bavaria and still belonged to the Bavarian king, Ludwig III, during World War 1. Being Prussian, Kaiser Wilhelm would not have occupied a Bavarian castle, and he split his time between his primary residence at the Neues Palais in Potsdam, and the Altes Palais in Berlin.
The film portrays Tsar Nicholas II abdicating the throne in front of Vladimir Lenin. In reality, the Tsar abdicated after the February Revolution of 1917 to the Russian Duma on a train coming back from the front. By then, Lenin had no direct involvement in the Revolution and was not even in Russia, being in exile in Switzerland. A provisional government took over, with Lenin taking power after a second revolution in October 1917. Of course, along with other liberties with real history, this might have been deliberate.
In his final scene, King George V is seen wearing a military uniform with the epaulette pins "VR" and "ER". The "VR" stands for Victoria Regina or Queen Victoria. The "ER" is not an incorrect reference to Queen Elizabeth II (Elizabeth Regina), but stands for King Edward VII (Edward Rex) who was the father of King George V and would have been King during George's service in the Royal Navy.
Towards the end of the film, Woodrow Wilson destroys the incriminating evidence against him by throwing a reel of film into the fire. Given that this would have been around 1917, the film stock used would undoubtedly have been made out of cellulose nitrate and so might be thought to have caused a serious explosion in the White House, but while nitrocellulose would burn very rapidly, it would not explode.
The assassination of Archduke Franz Ferdinand depicts Gavrilo Princip both throwing the first bomb and shooting the Archduke and his wife. In reality, these were done by different people. There were three conspirators, and by the time Princip shot the Archduke the first accomplice had already been captured. However, this is likely to be a deliberate alteration by the filmmakers to simplify the plot.
Erik Jan Hanussen was not an advisor to Kaiser Wilhelm II during the war and was not politically active until much later. The character appears to be a replacement for either Erich Ludendorff or Paul von Hindenburg. However, this is likely a deliberate alteration to fit the plot of the movie, as Hindenburg and Ludendorff have very well defined historical careers, unlike the less known and very shady Hanussen.
The flag flying at the US Embassy in London is the modern 50-star flag instead of the 48-star flag of the time period.
A road sign reading SAVILLE ROW W1 is seen in 1914. Postal districts in London were not numbered until after the war broke out and many postal workers left, as the new employees didn't know all of the streets in a region.
Oxford refers to the "Beryozka glide" when talking to Rasputin. The Berezka Dance Ensemble was renown for moving across a dance floor in long gowns, appearing as though floating. This is how Rasputin appeared, entering the room flanked by two women, gliding with no apparent steps. However, choreographer and dancer Nadezhda Nadezhdina didn't found the ensemble nor the specialized choreography until the mid 1940s and didn't tour the West until the early 1950s.
The exterior of the White House shows the Truman Balcony on the second floor of the south face. The Truman Balcony wasn't completed until 1948.
King George tells Oxford about the effectiveness of the German blockade and people being hungry in the street. This never happened, and while British trade routes were being attacked, the submarine warfare in World War 1 was not that good, and the British public never starved. However, this did happen in World War 2.
Lance Corporal Reid brings a message from Conrad Oxford to his father Orlando Oxford, and in describing the nature of the letter's contents uses the word "surreal." The term surreal was created by the French writer and critic Guillaume Apollinaire in 1927.