When the camera pans Patton's troops, there is an intermingling of black and white faces. But the Army was strictly segregated in 1945.
Klaus Barbie is wearing the wrong rank during the entire film. He was a Hauptsturmführer not an Obersturmbannführer. Barbie was the equivalent to a Captain not a Lieutenant Colonel. Big historical difference.
Barbie murders a group of seven people standing side by side in an empty swimming pool facing him. But he only fires six shots.
When the group crossed the border from French to Switzerland it was Montriond France. Not Montriand .
George Patton was known to historians for being antisemitic based on letters to his wife, and comments made by Truman and Eisenhower, at the time; and who would never have lauded Marcel Marceau, and his efforts to save Jewish children.
The Swiss hunter in the closing scene spoke with a Swiss German accent, whereas someone in that area would have sounded French (the actor was Swiss German)