Goofs

When the ape wrestles with Charron in the opening scene, some of the black make-up on his palms smears onto Robards' white shirt. But when they take their curtain call, the shirt is suddenly spotless.

When Cesar leaves the bedroom (where Marot is hidden behind the door) after checking on his daughter, he closes the door. At the next scene, when Marot is back beside the bed, the door behind him is open.

Since in Paris, there is no reason, for the English sign saying 'Buried Alive' on the fairground caravan.

When the murderer flees the theatre after the death of Erik at the start, it is obviously a stuntman, rather than Herbert Lom, who jumps over the fence.

At 2:19 when Erik tilts his head back to give his primal yell it exposes the actors skin on his neck just under his chin. Clearly a costume and not a real gorilla.

The use of a stunt-double for Lom is also obvious in the fight-scene with Robards in which Robards punches Lom and sends him crashing into a table.

Just before a performance, Charron tells his wife to "break a leg." That very American expression originated in the 1920s, and thus certainly would not have been spoken in 19th-Century Paris.

When Cesar & Madeleine enter a room (after watching a Punch & Judy show) the camera is pointed at a mirror on the wall. A blue box is on a table, as Madeleine moves towards the box a long thin mic is seen (a reflection in the mirror) coming in from the bottom right hand corner of the mirror following her. The mic is only visible in the mirror.

Although the movie takes place in Paris, none of the actors are French and few even attempt a French accent; most merely speak in their normal voices.