Factual error: The door of the garage next to the house is of the aluminum up-and-over type, not available until the late 1960's.
Factual error: When Goring arrives at Calais by train, you notice there is a huge mountain in the background. There are no mountains anywhere near Calais.
Factual error: In an early scene, there are some Spitfires which catch fire. They burn fiercely like the fabric covered Hurricane not the metal skinned Spitfire. Quote from my mother who served in WW2 on a Naval Air Station and saw them both burn. "Those Spitfires are burning like Hurricanes".
Factual error: The message at the end of the film acknowledging the contribution by pilots from outside the UK is wrong in a number of details. Most obviously they mention a pilot from Israel, a country which did not exist until 1947 (In fact he was from the British Palestinian Mandate). They also omit any mention of the nine pilots from Denmark, and two Jamaican pilots who took part in the battle, and there was one from Egypt and one from Austria involved, who was also forgotten.
Revealing mistake: Technical Glitch: In the opening scene before the opening credits. The British are being run out of one of the last remaining fields in France. The Sergeant is burning the "lame ducks" when German planes attack. A German plane attacks almost directly toward the camera, you hear machine gun noises but no effects. Next a plane attacks from right to left, you hear machine gun noises and see the effects indicating the bullets striking the target. After the second plane has gone you see the effects of the first planes attack.
Factual error: Early in the movie as the Germans are moving landing crafts up to the coast in preparation for the invasion of England. At least one of the trucks hauling landing crafts is a "B" Model Mack which was not introduced by Mack Trucks until 1953.
Continuity mistake: During the slaughter of the German bombers by Christopher Plummer's Spitfire squadron, the same footage appears twice. There is a shot of burning Heinkel plunging into the sea. Then there is another bomber being attacked by Spitfires and that one, too, begins to go down. We see it go into the sea, only it's the exact same footage as before.
Continuity mistake: When Michael Caine gets shot down, it starts with a shot from inside the pursuing BF109. You can see the Spitfire on the port side. The next shot is of it passing in front of the 109's gunsight, however the plane you see is a Hurricane. The shot after this, show the Spitfire back again and on fire flying quite straight. However, when you see Michael Caine's aircraft explode, it has again turned into a Hurricane and is diving.
Continuity mistake: When Christopher Plummer gets shot down, you see him burning in his Spitfire. The shot after this shows an aircraft spiraling out of control. The plane you see is a Hurricane, although he is flying a Spitfire. When you see him bail out, it is a Spitfire again turning gently to the left and is not on fire. When the plane blows up, it has again turned into a Hurricane and is pointing straight down.
Factual error: The German planes in the movie should be Messerschmitt Bf-109E. However, all the German fighters are Hispano Buchon, a post-war version of the Bf-109 model, built in Spain. It was powered by the same engine like Spitfire, the R&R Merlin. The noses of those 109s in the movie looks the same as the Spits, not like Bf-109. Bf-109 was powered by a Daimler-Benz inverted V, exhaust ports were at the bottom of the nose, not at top.
Factual error: Most of The Spitfires in the film are not the correct type - Mark 1's and 2's should be used but you get a mixture of mark 9's and 14's. You can tell the mark 1's from the 3 exhaust stacks, the later models had 6. There is one genuine Battle of Britain veteran spitfire in the film, P7350, a Mk IIA the only BoB veteran spitfire still flying and operated by the Battle of Britain Memorial Flight.
Revealing mistake: In the opening scene when the Hurricanes take off from the makeshift airstrip in France, well established earth-banked aircraft pens can be seen in the background. This indicates that the Hurricanes took off from a well established military airfield.
Continuity mistake: When Schmidt interrupts and delivers a report to a Luftwaffe meeting, the presenter is holding a wooden stick used for pointing on the table map. When Schmidt enters the room with the camera facing towards the door, the presenter puts his two hands at the top of the stick, supporting with his palms. Just before the next shot watch carefully and you will see both hands move off the stick. In the next shot with the camera now facing towards the table, the presenter has his left palm resting on the back of his right hand with the right palm supporting the stick. (00:51:35)Zim