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).
Continuity mistake: When Buffy wakes up she is wearing metallic nail polish, yet when she went to sleep previously, she has no nail polish on. Later in a scene where Buffy is dreaming about her night with Angel she has the nail polish on again, even though that took place the night before when she did not have her nails painted.
Visible crew/equipment: When Willow and Dawn are running away from the demon, Willow uses magic to unlock a car for them to escape in. On the right side of the screen, shadows of crew members can be see as the car's doors open and are gone when Willow uses magic to make the car drive away.
Revealing mistake: One of the arrows that Spike gets hit with passes through just below his left shoulder, but there are times when you can tell that it is a fake arrow because the part of the arrow sticking out at the front moves and the part at the back does not. Look at the arrow just after Buffy turns Hus into a bear.
Other mistake: Robin uses the song that Spike's mother sang to him to provoke him into attacking him. The song is played on his computer through Apple's media program "iTunes". He clicks his computer's mouse to start the song, but when we see the monitor the cursor isn't placed on the Play button. Robin doesn't jostle the mouse when he presses it, it remains completely still on the desk. And the only way to play a song through iTunes using a single mouse-click is by clicking on the Play button.
Continuity mistake: When Willow is out with Kennedy, Willow tells her that she doesn't get why she likes her. As she says "I still don't get it", she pulls her hair back over her left ear. Then when she says "Why you like me" in the following shot, her hair is hanging back down over her left ear again.
Visible crew/equipment: When Buffy and Dawn are at the top of the metal tower, and Buffy is still very dazed from being called back, there is an overhead shot with a piece of the tower falling down; if you look left of the falling piece, you can see a guy wearing a hard hat walking about.
Visible crew/equipment: When Xander and Anya pull over in the ice-cream van, the front windscreen is very reflective. To avoid reflecting the camera crew, a giant screen was put in front of the ice-cream van - which, ironically, is reflected in the windscreen. It isn't a reflection of another vehicle parked in front of them as the thing that is reflected is a curved shape.
Continuity mistake: When the Cavemen knock out Willow, she lands flat on her front. Later on, one of the Cavemen watches Willow as she lies unconscious, and she is now lying on her back. Then when Buffy finds her when the building is burning down, she is back on her front.