Continuity mistake: During Anya's pep talk to the Potentials, Andrew draws crude illustrations to visualize what she is saying. One the second page that uses to draw a picture of the sun, the top of the previous page that's folded over the back of the board changes from being folded straight to folded at an angle between shots.
Revealing mistake: When we see Spike and Andrew on Spike's motorcycle talking about Onion Blossoms, a filming light is reflected in Andrew's helmet.
Continuity mistake: In the episode 'Empty Places' when Xander is returning from hospital Kennedy is standing beside the couch to greet him and Willow. When Xander sits down she is sitting on the couch, but she wasn't out of shot long enough to have gotten there.
Visible crew/equipment: When Dawn and the Potentials try to get past one of the police officers at The Bronze, Kennedy says that he'll have to shoot them all to stop them. As he responds with "It doesn't really bother me", the shadow of a boom mic can be seen on the wall behind him in the top right hand corner of the screen.
Visible crew/equipment: After Buffy has spoken with Clem and is walking down the road, you can see the reflection of a camera in the back of a green SUV.
Chosen answer: From what we see in the series, certain girls are identifiable as potential Slayers - Kendra clearly fell into this category. The identification method is presumably mystical in nature, but the Watchers' Council are pretty effective at that sort of thing, so they're quite good at tracking down the potentials ahead of time. Not perfect, though - it does appear that Buffy herself may have slipped through the net - certainly she had no inkling of what she was until she'd already taken on the role of Slayer. It is possible, however, that this was actually cultural - an American family would hardly be likely to turn over their daughter to some strange man for 'training', so the Watchers might have chosen to keep an eye on her covertly, whereas some other cultures (like Kendra's Jamaican parents) might be more willing to believe.
Tailkinker ★