Continuity mistake: In front of the locker she broke into with Daphne, Velma holds Olivia's blue ribbon in her left hand. She turns towards the locker and is surprised by Two-Mop Maggie. She is not holding the ribbon in her hand anymore, and her right hand is covered by an oven mitt. (00:37:15)
Continuity mistake: In the first part of the denoument, with the two girls confronting Bloom, Velma says "Of course. Olivia was a musical prodigy." Her right hand is inside the backpack, which she is holding by the top using her left hand. Cut, and her right arm is across the bag. (01:03:40)
Continuity mistake: Daphne is talking with mom and dad after the second day of school. At least two takes of the scene have been filmed, because the ice pack on Mr. Blake's knee is tilted in two different ways on his knee, and they keep being mixed together in the final edit. (00:31:40)
Continuity mistake: It's no wonder that the two protagonists were caught red handed in front of the locker when they broke into it the first time; it was 10 past noon when they began, it's 20 past when they are done (of course it can't be this long, it's a continuity error). (00:36:15 - 00:37:20)
Continuity mistake: Sabotaging "Violet Johnson", Velma and Daphne are peeking from the door of the lab; the reverse shots with the hand in foreground don't match the rest - the hand looks to be operating the equipment but it is not when the table with the teacher is shown. (00:48:50)
Continuity mistake: As they get motivated to go look for the bad guy at the end, Velma tells Daphne "I am stronger than I ever thought I was", with the strap of her bag passing inside the collar, and not outside and by the top button like in the rest of the scene. (00:58:00)
Continuity mistake: Velma gets in the back of Mikayla's art installation looking for the power cables, and Daphne follows at distance. In the close-up, the shadow on the back of the projection screen is closer to the edge than in the preceding aerial angle. (00:49:40)
Continuity mistake: When Velma slams the big pile of work on the chemistry teacher's desk, the paper on top of it is a couple inches off the side closest to the professor, but it's perfectly aligned with that side after the cut. (00:48:15)
Continuity mistake: The time counter during the call to Daphne's mom from the secret school room jumps from 5 seconds to 13, 31 to 44, 57 and 1 minute and 18, with no possibilities for time to pass during each line/cut. (00:56:40)
Continuity mistake: When Velma presents a new mop to Two-Mop Maggie turning her back into Three-Mop Maggie, the ribbon in close-up has the two longer bits across the handle, which becomes just one in the other shots. (01:10:15)
Continuity mistake: Outside Bloom, Daphne says she can hear her dad "loud and clear." The zipper of her jacket in the next shot is closed more. (00:59:00)
Continuity mistake: Once Mikayla is getting 'eaten' by the tube, Daphne holds Velma's arm clinging to her sleeve; at the cut, her hand is relaxed instead. (00:53:25)
Continuity mistake: Velma is holding the scooter the 'ghost' was using; her hands are placed in different positions between shots. (00:55:30)
Continuity mistake: When the kid says "Do you wanna go out sometime?" to Lunch Lady Velma, a girl with brown hair, nerdy glasses and a shirt with rainbow stripes walks by behind him. A couple of shots later, there she is again, walking along the same path again. (00:39:40)
Continuity mistake: Just before introducing Tobias Bloom, the principal has blue earbuds in her hands. She is holding them as she begins to gesture towards the stage entrance, but they have vanished with pure sleight of hand (or rather, editing) in the following shot. (00:33:10)
Continuity mistake: In the principal's office after melting the locker, Daphne and Velma are being scolded. Miss Piper's glasses rest on the desk in a different way depending on the angle (in the frontal shots the right side is more elevated). (00:37:45)
Continuity mistake: Time to sit up from the Conflict Couch; Daphne in the close-up lying down has all her hair off the shoulders, but coming up she starts off with a lock of hair along her neck and in front of the right part of her body. (00:27:35)
Continuity mistake: When the girls melt the locker for the second time, the circuit is undoubtedly positioned under the lock, but as the principal walks behind them saying "What!", you can see it poke from the side of the open door. (00:44:00)
Continuity mistake: When Carol demonstrates the various texturing options, different takes of the same angle have been used, since Daphne holds the changeable T-shirt with her finger sticking into the neck or not between cuts. (00:21:05)
Continuity mistake: Once Daphne gets splashed with water on her shoulder at the cafeteria, she shows up at the laboratory with her shirt more wet than earlier. The water stain is even bigger by the time she sits with Velma. (00:21:45 - 00:31:40)
