गूफ़

When Fredric March is being interrogated, the inkwell in front of him is uncovered, when the camera switches between him and his interrogator, the inkwell's cover is on.

After the fight, Cernik tells Barovic that he needs to take his revolver. In fact, it is a semiautomatic pistol.

As the circus performers rush to freedom, Vosdek shoots at the Czech guards with a six-shot revolver, but fires more than six shots.

The wolves in the circus clearly are domesticated dogs (perhaps German Shepards or Belgian Malinois???). But not being dogs, wolves are not very trainable and obviously the director wanted his "wolves" to perform on cue (something dogs can and will do whereas wolves will not!).