Continuity mistake: When the Buffybot is at the parent teacher day and she is looking at the student model of a Utopian city, the hover cars are moving around the model on a wire. But when the shot changes, the cars aren't moving. Then in the next shot, they're moving again.
Continuity mistake: In Bargaining, part 1, Anya is talking to Giles while he trains the Buffybot. There's a shot from behind and we can the corner of her jumper move around as she turns away, then it cuts back to a front view of her and she's still facing Giles.
Continuity mistake: After the 'hell hogs' interrupt the ritual, Xander pulls Willow out of the way. He then tells Anya and Tara to "take off." which they appear to do, starting to run into the woods. But then in the next shot, they are back standing still in the clearing (on the left of the shot).