In the final scene, when Capitano Benucci realized an escape is happening, he is seen running around the camp with his pistol in his hand. The pistol is an automatic, but when he shoots the "traitor" hidden behind the blanket, the closeup shows a revolver.
Towards the end of the movie Peter Arne is walking through the concert hall. He pushes the handle of the artificial clapping machine. The handle stops almost straight away yet the clapping noise continues for several seconds.