Factual error: A convoy of open trucks arrive at the camp bringing the latest batch of prisoners, many of whom are carrying rucksacks and tote bags of clothing and other possessions. Where did they come from? Combat servicemen in World War Two did not carry overnight bags with them - a change of clothes or a handy supply of toiletries was the least of their concerns. A prisoner of war arrived in the camp with the clothes he stood up in and nothing else.
Factual error: Why is Hilts not wearing a uniform? A serving officer captured behind enemy lines in civilian clothing risked being shot as a spy. If a prisoner's uniform was too worn or damaged to wear, it was routine for the German authorities to replace it - a P.O.W. in civilian clothes is an obvious escape risk. He is wearing a pair of tan chinos, a cut off sloppy Joe sweatshirt, both ridiculously anachronistic - Sixties hipster fashions - and nowhere even close to a World War 2 uniform. He is also wearing Army Type III Service boots - something that would never have been issued to a fighter pilot.
Factual error: Many of the prisoners are wearing watches, which is incorrect. Upon arrest a prisoner's watch was confiscated. This prevented them using them to bribe or barter with corrupt guards (and as this film acknowledges, there were plenty of those) as well as making coordination of meetings or escape plans difficult.
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.
Factual error: As Steve McQueen is making his 'great escape', he drives his motorcycle through a gap which a chasing motorcycle and sidecar can't squeeze through, so it crashes. Cut to a crane shot of the retreating McQueen racing into the distance. Keep your eye on the left of frame and into view, on top of a building, is a distinctly un-1940s TV aerial. It's there for a full 7 seconds.
Factual error: The entrance to tunnel Dick is shown improperly; the trap door was on the side of the drain basin, not the bottom. This was discussed in the Brickhill book, and subsequently verified by research on the site (shown on the US television program NOVA) which found the original door and its lifting handles.
Factual error: When the SS and Gestapo are leaving Bartlett in Von Luger's office on his arrival in the camp, they all give the Nazi salute with bent arms. The correct form was a straight outstretched arm and hand: only Hitler himself was allowed to give the Hitler salute so sloppily.
Factual error: In the scene at the railway station, the carriages bear the 'DB' logo of the Deutsche Bundesbahn which is definitely post-war. During the war they would have carried the Deutsche Reichsbahn logo.