Factual error: At the beginning of the movie there is information, that "Poland surrenders to the Germans after less than a month of fighting." In fact, the last big battle during Invasion of Poland (Battle of Kock) took place between 02-05 October, more than a month after first shots were fired. And Poland also never officially surrendered to the Germans. (00:03:30)
Continuity mistake: After the recital is broken up, one of the Jews is killed outside and the second is forced to play the violin. The blood spatter on this Jew's face changes between shots. (00:37:00)
