The Great Escape (1963)

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.

Group Capt. Ramsey: Colonel Von Luger, it is the sworn duty of all officers to try to escape. If they can't, it is their sworn duty to cause the enemy to use an inordinate number of troops to guard them and their sworn duty to harass the enemy to the best of their ability.
Col. Von Luger: Yes I know. The men under your authority have been most successful. This man, Ahsley-Pitt for example. Caught in the North Sea, escaped, recaptured, escaped, recaptured. Archibald "Archie" Ives: 11 escape attempts. He even tried to jump out of the truck coming here. Dickes, William: known to have paticipated in the digging of 11 escape tunnels. Flight Lieutenant Willinski: four escape attempts. MacDonald: nine, Hendley, the American: five, Haynes: four, Sedgewick: seven. The list is almost endless. One man here has made 17 attempted escapes. Group Captain, this is close to insanity.
Group Capt. Ramsey: Quite.
Col. Von Luger: And it must stop!

Trivia: While Steve McQueen performed most of his own stunts, the only stunt he didn't perform was the 60 foot jump over the Austrian-Swiss border fence. The jump was performed by stuntman Bud Ekins, who later doubled for McQueen in "Bullitt."

Question: How come Hilts could not answer the German at the end of the movie when he said he could speak German to Colonel von Luger?