Continuity mistake: When Fred and Daphne stumble across Mel Richmond, they open a door and startle each other. They talk for a moment, and each time the camera changes angles, Mel is suddenly further out the door without moving, and Fred and Daphne keep moving back without moving. (00:17:15)
Continuity mistake: As Shaggy and Scooby order the gigantic pizza, the waitress holds up a release form. Every time the shot changes, the position of her fingers changes on the form. (00:20:35)
Continuity mistake: Before the pizza is brought out, Shaggy and Scooby are sitting at a long table. The center of the table has the usual stuff, salt and pepper shakers, napkins, etc. But when the gigantic pizza is brought out, this stuff suddenly vanishes. (00:21:15)
Continuity mistake: Lotte barges in the pizza place and carves her name onto Shaggy and Scooby with her sharp nails. LOTT on Shaggy's shirt, and the E in Scooby's fur. They run out the door and then come back to pay for their food. Suddenly the rips in Shaggy's shirt and the scraped off fur on Scooby's chest have vanished. (00:23:45)
Continuity mistake: When the gang are on their hotel bed researching the Phantom, Velma says she thinks someone is using the old stories to take advantage, and looks over at Fred. It cuts to a slightly closer angle, and suddenly she is looking straight at her laptop again. (00:24:35)
Continuity mistake: The whole time Daphne and Velma are on the balcony of their hotel room talking, the wind is blowing their hair and clothes quite strongly. But just before the scene changes and Daphne grabs Velma saying that have to win the competition, the wind has instantly stopped. (00:27:30)
Continuity mistake: After Chrissy gets finished with her song, Velma, Fred, and Daphne are shown behind stage staring in shock at how inappropriate the song was. It cuts to a close up of the three and suddenly Velma and Daphne are much closer together and in front of Fred, whereas they were beside him a moment before. (00:33:45)
Continuity mistake: After Chrissy's performance, Dewey is at the podium holding a clipboard and says that Emma Gale is up next. It then cuts to a close up as he asks if anybody has cleaned the microphone. Between shots, his hand goes from being near the top of the clipboard to being at the center. (00:34:00)
Continuity mistake: While Emma is on stage giving her violin performance, Daphne, Fed, Velma, and Emma's parents are off stage watching. It cuts to a close up and suddenly Emma's dad's hand is on her mom's shoulder. (00:34:35)
Continuity mistake: When the gang try to set a trap for the Phantom in their dressing room, it doesn't go right and Shaggy runs to the couch scared. There is a conventional clock behind him on the wall, the hands showing 1:10. It cuts to a view from inside the closet and suddenly it shows 1:15, the minute hand jumping from the 2 to the 3. (00:43:00)
Continuity mistake: In the sewers under the Opera House, a bunch of rats rush out of a duct at the gang and it startles Shaggy. He backs up into the guard rail and knocks a large chunk of it loose, which falls away, leaving a large gap in the railing. Scooby quickly grabs Shaggy and pulls him away. Then the gap is shown again, and it is suddenly only about half the size it was in the previous shot. (00:44:30)
Continuity mistake: In the sewers, the gang happen upon a part of the wall that has been collapsed, leaving a large pile of rubble in their path with an opening beside it. Fred, Velma, Daphne and Shaggy go all the way across, climbing over the rubble. Scooby stops at the top of it for a moment, and peers into the hole beside him. This scares out a cloud of bats that fly out at the gang. They fall over the railing, but are shown suddenly falling from the pile of rubble, when they had already passed that point except for Scooby. (00:45:05)
Continuity mistake: Velma goes into the sound room to investigate Brick. She finds the microphone still on and taps it. Between shots, the mic's receiver part changes from being a sphere to a cylinder. (00:54:25)
Continuity mistake: In the Mystery Machine, Fred swerves around a car at an intersection and passes it. He then looks back to see if Dewey is following them, and the car they just passed vanishes. (01:03:15)
Continuity mistake: In the car chase at the end, Fred takes the Mystery Machine into some heavy traffic. Shaggy says he can't watch so Scooby puts his paws over Shaggy's eyes. For the next few shots, his paws keep alternating from being over Shaggy's eyes and not between close ups and views from the front of the van. (01:03:45)
Continuity mistake: Dewey's car begins rolling down the bridge - there are parts and debris that come off and are seen rolling with it. But just before the car hits and explodes, the debris falling with it vanishes. (01:04:40)
Continuity mistake: When Emma finishes her performance after the big car chase, she jumps off the star and slides on her knees to the edge of the stage. It cuts to a much further back shot, and suddenly she is quite a ways away from the edge of the stage, back next to the star. (01:06:55)
Continuity mistake: After Emma finishes her performance, Brick comes out on stage and gives the conclusion so she can leave. When he comes out, he stops and she is standing still on his right side. Camera cuts to a far shot and suddenly she is on his left side, and then turns to walk off stage. (01:07:00)
Continuity mistake: Before doing their tie breaker performance, Fred and Daphne get up on stage and are introduced by Brick. It cuts to a close up and suddenly Brick is standing right next to them. (01:10:15)
