Revealing mistake: Oliver Reed heroically pummels a venomous snake made of rubber (therefore invulnerable to his heavy hits). (00:58:30)
Revealing mistake: When everyone enters the Judge's room and looks at him lying lifeless in bed, the room is in the dark. The light increases when the candles have been on the bedstand for a couple seconds already. (01:12:50)
Revealing mistake: It's supposed to be the middle of the night when Elsa disappears, but the day for night effect is lacking to the say the least; the sun glow can be seen around the building, and the perfectly white clouds when Elsa is walking through the ruins. (00:33:00)
