Continuity mistake: When Ben brings him and Dawn some hot chocolate, the cups containing the hot chocolate are in fact two cups, one inside the other, making a total of four separate cups. But once Ben reveals that he is in fact Glory, Dawn's two cups have suddenly changed to just one cup.
Continuity mistake: In the first scene of the episode, just after the teaser, the Scoobies are gathered around the table at Giles' magic shop. During the second part of the scene, we can see Anya is alternatively lying her arms under or above the table depending on the camera angle, whether from behind or facing her. (00:01:55 - 00:03:15)