When Giles is going through the Magic Shop ledger, his left hand keeps jumping around; nearly every time the shot changes, it suddenly is in a different position.
When Giles is driving to the Magic Shop with Buffy and Dawn, Giles says, "Dawn, would you stop fiddling with the radio and sit down." When the shot shifts back to Dawn sitting back, Giles' is seen still saying "sit down" even though the audio's already been heard.
When Xander arrives at Buffy's house to babysit Dawn, as Joyce is leaving Xander says, "Have fun. Not too much fun though." (It's even in the captions). But Xander's face is visible onscreen and his mouth isn't moving.
When Giles, Buffy and Dawn are in the car on their way to the Magic Shop a crew members hand is visible on the car behind Giles at 8:56.
At the beginning, Buffy and Giles are training in a room, which is later shown to be the back room of the magic shop, however at this point Giles doesn't own the shop, so it doesn't make sense that they would have been training there at that time.
At 18:26 the tip of the boom microphone dips into the shot as Willow starts toward Tara.
Dawn relates that her mother, Joyce, once reacted negatively to Dawn's stated interest in learning how to do the things Willow and Tara "do together". Since immediately before this Joyce expressed no disapproval of Willow and Tara doing a magic spell, and no awareness of their romantic relationship, her disdain doesn't make sense.