In the first scene we see a completed white domed church of Sacré Coeur atop the hill. The basilica was not completed until 1914, 14 years after the story takes place. (It is also shown directly across the Seine from the Eiffel Tower, which is northwest. It is actually northeast of the Eiffel tower and would not be visible in this view.)
In the "Elephant Love Medley" scene, Satine and Christian are obviously lip-syncing. A few times, they miss saying the word all together, or they are just a part of a second behind the pre-recorded vocals.
When Satine says, "You're going to be bad for business", we see her from behind - but it is obvious her lips are not moving. (The remainder of the phrase, "I can tell", is shown from the front and her lips do move).
When Satine is dressing to meet the Duke for the first time, she wears a red dress and asked Zidler for his approval ("Smoldering temptress?"). Then when she goes to meet the "Duke" in the Elephant, she has changed into a black gauzy outfit with a different hair style. Later that evening, singing with Christian atop the Elephant, she's back in the red dress again and her hair is done to match the first scene.
When Satine sings the line, "I hope you don't mind, I hope you don't mind... ." to the Duke, he is holding a wine bottle and she is barefoot. When she jumps on the bed, he is bottle-less and she wears shoes.
During the performance of Spectacular Spectacular! when the Argentinian enters he can be seen walking down the stairs and joining the rest of the dancers. A moment later when the shot cuts to a different angle, he can be seen walking down the stairs again.
When Satine is putting on the red dress with Marie, Satine turns around with her right arm raised to ask Harold how she looks, then the scene cuts to him for just a second. When the scene cuts back to Satine, her left arm is raised.
During the 'Spectacular Spectacular' dress rehearsal, contents of the theatre behind the Duke changes with every cut. Sometimes there is nothing, sometimes there is a horse/donkey, sometimes a stack of chairs and sometimes there are the chairs laid out neatly.
During Spectacular Spectacular, as Toulouse is yelling "The greatest thing you'll ever learn is just to love and be loved in return" you see him start to grab the rope. When he starts to fall after Christian sings "Come What May" we see him not holding the rope, then suddenly he has the rope in his hand when he's falling towards the stage.
During "Spectacular Spectacular" the doors can be seen closing behind Satine and Christian as Christian throws down the money. It can be seen closing again in the next shot when Christian has walked off stage and Harold comes to Satine.
During "Hindi Sad Diamonds", there is a close-up shot of Zidler turning around to look at the Duke, who is sitting in the front row. The next wide shot shows Zidler's red turban facing Satine (upstage) at the bottom of the screen. The next shot is again a close-up with Zidler facing the audience and looking at the Duke.
Near the beginning of "Roxanne" Nini is pushed away from the Argentinean into another man's arms. The next shot is shown from a different angle and she is standing alone. The man is behind her and moving toward her.
When Christian is mouthing the words of "Your Song" to Satine you can see that the fruit bowl has an apple and grapes on top of 3 oranges but during "the pitch" you can see that the oranges are on top of the grapes and the apple.
During "The Show Must Go On," when Satine walks down the aisle of the theater towards Harold and the doors, she pauses for a moment in front of him. The camera moves to Harold's face for a moment, and then back to Satine, who is now standing level with him.
Just after Chocolat leaves the passed out Satine (recovering from her fall from the swing) and returns to the dance floor he goes from having a rhinestone top hat on to having no hat at all and back again about 4 times.
When Satty begins to play the piano in El Tango de Roxanne, Christian can be seen strolling along the sidelines of the ballroom. He passes the same man and woman three times, twice in a far shot and once close.
During the Elephant Love Medley when Christian and Satine sing "We could be Heroes", Christian can be seen moving unevenly from the doorway to a handbreadth away from Satine's face, and in the following shot approaches her slowly from a different angle.
Cameraman's foot and leg visible in the background of the Can Can scene. (Seen in the Extended Can Can in the 2nd disc. Appears when the Can Can Girls begin to lay on the floor kicking their legs in the air.)
In the scene where Nini asks the Duke "Why would the Courtesan choose the penniless writer - oops. I MEAN SITAR PLAYER!", the cast is performing on stage. They have platforms going so far up you can't see the top at the camera level at the stage. You can see a cameraman's shadow from a platform that is higher than camera level.
It has been suggested that the long white coat Christian is wearing on stage (the one he took from the Narcoleptic Argentinean) mysteriously disappears before he begins singing to Satine, but in fact we see him take it off as he walks down the aisle. It does disappear from the floor, but perhaps some helpful theatergoer picked it up while we weren't looking.
During the Green Fairy "Sound of Music" song, while Christian and the Bohemians are standing and singing outside of the "L'amour" apartment, Toulouse raises his leg and you can see a knee instead of his foot.
As Satine and Christian descend from the top of the elephant and enter the chamber inside, the hanging ornaments above the entrance can be seen to start moving by themselves - this is from the wires that the actors had to wear when atop the elephant but which were digitally removed from the image.
During "Roxanne", when The Duke is telling Satine his plans to make her a star, the table before her has only a few candelabras and a platter of red pastries. When the table is shown again, as Satine is sweeping items off to hinder The Duke's pursuit towards her, many more platters and plates are seen than before.