At the end of the film when the last German soldier is shooting at Lt. Hoffmen, he fires several continuous shots with a Mauser bolt-action rifle, without moving the bolt after each shot. It would be impossible to fire a bolt-action rifle without moving the bolt after each shot to eject the spent casings.
As depicted, the electric fence would not work. It was also unrealistically tall, but my guess that was done to help with the gymnastic component of the film.