When Salomon rides his bike through the sheet of glass he cycles on past the shoe shiner, in the next shot he has fallen off his bike lying in the glass 6-8 feet in front of the shoe shiner.
When the Russian refugees are fleeing Poland and are strafed by a German fighter plane, the fighter plane is obviously a smaller scale radio controlled model. The airplane resembles a Supermarine Spitfire, an airplane not used by the Germans.
When 'Jupp' leaves the police station after he admits to not possessing 'racial purity' papers, the town is bombed by a modern-era Hercules C-130 transport aircraft.
At one point Salomon narrowly misses being killed in an air-raid, which kills his roommate. Rather than show a World War II aircraft, or even a bomber, stock footage shows a single C-130 Hercules transport aircraft, which was not even designed until many years after the war.
In the classroom scene, where the teacher is demonstrating racial profiling techniques on Peters using calipers to measure his head, the calipers sometimes move and produce no sounds. Other times sounds are heard when the calipers aren't moving. Also, many of the sounds that are heard are inconsistent with the sounds that instruments like these should produce and how they should be properly used.