Revealing mistake: When all the vampires are saying "for the dark", and one gets staked, there's a mark on his shirt where the stake's about to come through before it actually happens. Plus Buffy's hands are in the wrong place for her to have pushed that stake through, as well as there being no stake in her hand when the vampire gets dusted. Not only that, but the mark isn't even close to the vampire's heart to begin with. (00:34:50)
Continuity mistake: As the prisoners are being moved off the transport and are strapped to these large metal frames, the frames move along a railing in a fixed position to each other, and also have a chain linked between each one running along the railing. One of the prisoners recognizes Stanley and starts shouting when his frame breaks loose. The camera shows a close up of the bar connecting his frame to the railing as some parts break out of it before it falls, and the chain that is connecting them has vanished. (00:22:50)