Other mistake: When Hilts and Ives are taken down to the cooler for the very first time, just after arriving at the camp, watch the wall as the door is closed by the guard behind Ives - it very obviously moves as the door slams shut.
Character mistake: The scene in the outdoor Parisian cafe is incredibly daft. First, the cafe owners call James Coburn's bizarrely-accented Australian to the telephone to keep him out of the way as their accomplices assassinate three uniformed German officers seated in the cafe in a drive by shooting. They then toast the killings with cognac, and that is the mistake - not the shootings, not the luring away of Coburn - the mistake is that the cafe proprietors celebrate the assassination of the German officers in broad daylight, in the open, without even stopping to think that such an action would have them shot, because all of this is done in the direct view of passers-by in broad daylight. Do they think those three German officers were the only ones in Paris? How did they know Coburn wasn't an undercover Gestapo agent or a French collaborator? Don't they stop to consider that in an occupied city machine gun fire is going to draw some attention from the authorities, who might just wonder what a couple of bullet riddled corpses are doing lying about the place?
Visible crew/equipment: Late in the film, when the two escapees are boarding a bus, there's a studio lamp on a scissor-lift in plain sight at the left side of the screen.
Continuity mistake: When Roger is in the van talking to Macdonald, his face is deliberately dirty and stubbled - but when they are about to shoot him, he is clean-shaven. similarly with his bruises which seem to magically disappear by the evening of the first day.
Character mistake: When Sedgwick is bringing the cement tunnel lid to Willy, somebody yells out "Hey Hendley" and Sedgwick answers "Hello boys". He was called by the wrong name.
Other mistake: Ramsay sports on his tunic the ribbons for the Distinguished Service Order, the Military Cross, either the 1914 or 1914/15 Star, the British War Medal and the Victory Medal. Unfortunately, the ribbon bar for the last three has been sewn onto his tunic upside-down - it reads, left to right as seen, VM, BWM, Star, when it should read Star, BWM, VM.
Continuity mistake: In the end of the movie, Hilts (Steve McQueen) is returned to the camp - he is dirty and his shirt is torn. When he enters the cooler, after being tossed his baseball glove, he is clean and his shirt is no longer torn.
Visible crew/equipment: In the scene where everyone is lining up to receive the moonshine that the Americans made you can see a crew member on the left hand side. He is wearing a red baseball cap and modern clothes. He is motioning for the extras to go into the main shot to get the alcohol. (Widescreen edition).
Factual error: When McQueen steals the motorbike from the German soldiers and rides off it is clearly a Triumph, a British make, not a BMW or Zundapp which was what the German army used. More to the point it looks like a 1960s model.
Visible crew/equipment: The first time Hilts (Steve McQueen) is locked up, you can clearly see the edge of the wall, and to the left a stage hand moving.
Continuity mistake: In the scene where Steve McQueen is pulling wire across the road, and attaching the end to the pole to trip up the motorcycle rider you can clearly see two shadows on the ground of Steve in opposite directions due to the camera lights.
Character mistake: When Werner goes to see Hedley for helping finding his "lost" papers, Hedley is playing chess. The chess set is set up incorrectly. When the men are set up properly, each player has a light colored square in the right-hand corner. In the movie, the game is set up so that the light-colored square is in each player's left-hand corner. This "beginner" mistake puts the king and queen in the wrong positions.
Plot hole: The officers arrived in separate vehicles where they could view the countryside and the road leading to the camp, yet they later claimed to Hilts they knew nothing about the area.
Continuity mistake: When Henley attacks the guard at the airport, the back of his jacket gets wet from rolling around on the ground fighting the guard (there are puddles visible). Yet a few moments later, when he is walking towards the plane, his jacket is dry. (Visible in widescreen DVD version - 2:25:26 to 2:25:56).
Revealing mistake: When Hilts is first locked in the cooler he turns to verify the door is locked. Apparently the set wall was so flimsy the stage hand seen on the left was required to hold the wall as Hilts pushed the door, to prevent it from moving. The stage hand looks like the German guard without his rifle.