Continuity mistake: After being abducted during the Don Juan performance, Christine changes into the wedding gown and the Phantom places the veil on her head. The veil gets thrown aside by the time Raoul arrives. Between the time Christine leaves and the mob arrives, there is a shot of the mannequin with the veil perfectly positioned on the head (although it is highly unlikely that someone took time to put it back.) When Meg walks through the lair and retrieves the mask, yet another shot of the dummy shows that the veil has disappeared.
Continuity mistake: At the end of the music of the night scene, the Phantom lays Christine down on the bed and sings the line, "help me make the music of the night." While singing this, he moves his finger down Christine's jaw line, and his finger comes off her chin. Yet when the camera angle changes, he is just starting to move his finger down her jaw, starting up near the ear. He wouldn't have had time to move his finger back up that quickly.
Continuity mistake: During the Masquerade, there is a close-up of two of the dancers, who sing "But who can name the face?" while standing next to each other, without moving. Next shot, they are several feet apart and the lady is dancing towards where the male dancer is standing.
Continuity mistake: When Raoul is tied to the gate, the ropes across his chest change frequently. Sometimes there are 3 running parallel to each other, from his shoulder to the waist. Other times there is a big knot in the top rope. Still others there appear to be 2 ropes across with a third running straight down his chest between them.
Continuity mistake: During the scene where Meg is looking for Christine backstage, we see her pass Firmin and Andre. Behind her Raoul approaches the managers and they turn to greet him. In the next shot they are turned round flirting with the chorus girls, Raoul is nowhere to be seen, and Meg passes behind them again.
Continuity mistake: When Christine approaches her family mausoleum, behind her you can see an above-ground tomb that has chains around the top cover. There is something on top of the cover that looks like a bouquet of flowers covered in snow, and there is not a lot of snow on the tomb. Later, when Raoul and the Phantom are fighting and the Phantom slashes Raoul's arm. Raoul falls backward onto this same tomb, and when we see him from above, rising, the chains on his side are missing, and there is suddenly lots more snow all over the tomb. The bouqet (or whatever it is) is missing. However, in the next shot that shows the same tomb, now there is much less snow, the bouquet is back, and one-half of the side chains have reappeared. You can see the continuity by the tree at the head of the tomb, and the triangular wreath laid at the head of the tomb.
Continuity mistake: When Christine is in the Phantom's lair for the second time, after the Phantom puts the veil on her head, the camera has a close up of him (during the lines 'an eternity of this before your eyes') and the back of Chirstine's head can be seen not wearing the veil. When the camera pans back to her, she is wearing the veil and removes it a little later.
Continuity mistake: When Christine is taken to the Phantom's Lair the first time (at roughly 38 minutes into the film), as the Phantom sings, he leads her by the hand from the gondola to the "Christine" mannequin. On their way, near the pipe organ is a Roman-style bust of a man's head with a dark strip of cloth askew over its left eye. When the Phantom sings "Let your soul take you." and "Savor each sensation." the strip of cloth is wide (like a sweat band), but when he sings "Let the dream begin." a 10th of a second later, the cloth has become very narrow - thin, like a bow tie. It turns back into the sweat band version again after Christine's nap.
Continuity mistake: After "Think of Me", Meg is pushing through the crowd backstage, searching for Christine and she finally makes her way out of the crowd. Their actions repeat in a shot from a different angle. The next shot is a close up of Andre sharing a cigar with a woman and in the background, you can see Meg pushing through the crowd again, even though she already passed Andre.