The man with the glass spectacle over his eye is usually shown with the spectacle over his left eye -- one time, though, he's wearing the spectacle over his right eye.
In the final stay at the apartment, where Max and Lucia are essentially imprisoned by their own decision, Max is shown always shaven. However it is said that their electricity is cut (scene shown) and water cut off (a character says it). It is doubtful that he dry shaved each day; his face would be extremely reddened and raw.
The prison number tattoo of the main character is erased, but in later scenes no scar is seen on her arm.
In the flashback with the ballet dancer, dancing in a kind of gym, there is a shot with a poster of Heinrich Himmler against a pillar. There are also two guards standing on the right. A bit later the same angle and the poster is gone and the guards have disappeared.
A poster for 'The Magic Flute' shown early in the film gives the composer as 'A.W. Mozart.' The performance is listed as taking place on November 20, 1960, but just a few minutes earlier, a caption announced the setting as 'Vienna 1957.'
In the beginning of the movie when the group of opera visitors enter the lobby, Atherton asks for the keys to room 25. Max hands him the keys to room 112, however.
In the flashbacks, Max is wearing the War Merit Cross First Class with Swords upside down on his SS uniform.