Continuity mistake: When Cassie and Dawn were talking, just before Cassie got kidnapped, Cassie put her hand on Dawn's shoulder, but in the next shot, her hands were by her side.
Continuity mistake: Towards the end, when Buffy stops the arrow, when she first grabs it her hand drops down to Cassie's mouth level, and her arm's bent at the elbow. When we cut to another angle it's now held at arm's length and at about eye level.
Visible crew/equipment: When a guy asks Dawn out to Winter Formal and she says "What?" - you can see a microphone at the top of the screen. (00:33:35)
Chosen answer: He had larangitis and because of the shooting specifications they had to have him shoot the scene with a bad throat, they then re-recorded his lines and dubbed them. At various points during the scene and indeed the episode you can see him touch his throat or rub it.