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. (00:26:20)
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: 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 Spike is looking out the window at the demons rampaging in the street outside Buffy's house, Dawn can be standing behind him with her hair trailing down below her breasts. In the next shot, when Spike pulls her away from the window, her hair is pulled back behind her shoulders despite her not having moved. (00:53:10)
Continuity mistake: When Dawn was at the house, she had a grey top and a red skirt, but outside, she had a red top and black pants.
Continuity mistake: In the alleyway scene after the real Buffy kills all the Hellions (biker demons) and runs off, one of the Hellions can be seen getting up behind Xander. We then see a closeup shot of the Hellion opening its eyes while still lying on the ground and then they stand up and sneak up behind Xander again.
Continuity mistake: Buffy's shoes change from being nice shoes, to runners (e.g. When Buffy climbed out of her grave, she had nice shoes, but when she jumped over the fence, she had runners on).
Continuity mistake: When Buffy sat down on a car and set off the car alarm, she didn't have any dirt on her hands and only a little bit of blood, but in the next shot, there was a lot of blood and dirt on her hands.
After Life - S6-E3
Continuity mistake: Watch Spike's hand when he punches the wall. The punch lands with his middle knuckle in the wall, but when he looks at his hand it is mostly the largest knuckle that is bleeding. (00:24:55)
After Life - S6-E3
Continuity mistake: When the demon is attacking Buffy in her room right after Willow's spell has made it corporeal, there's a shot from behind of it drawing back its left hand, followed by a shot from the front of it delivering the backhand with its right hand. (00:34:40)
After Life - S6-E3
Continuity mistake: When Anya was possessed, she cut her right cheek, but in the next shot, her left cheek was cut and she was cutting her right cheek again.
After Life - S6-E3
Continuity mistake: When Dawn and Buffy were talking in Willow and Tara's room, Dawn's necklace went from being above her top, to underneath her top.
Continuity mistake: In 'Flooded', Jonathon reads a few things off the board listing the Trio's ultimate aims. One of the things he reads out is "prototype jet-packs that actually fly", but when the list is shown a few seconds later jet packs aren't mentioned on it. (00:27:10)
Continuity mistake: As the Trio are discussing their plans near the end of the episode, Jonathan's arms are crossed in closeups and in other positions in wide shots. (00:36:35)
Life Serial - S6-E5
Continuity mistake: Warren switches from holding Jonathan's magic bone with one hand to two hands between front and reverse shots. (00:19:10)
Life Serial - S6-E5
Continuity mistake: While working at the Magic Box, Buffy's horseshoe necklace constantly shifts between left, middle, and right positions, even within the time loops. (00:20:20)
Life Serial - S6-E5
Continuity mistake: When Buffy and Spike are in his crypt drinking whiskey, after Buffy says to him, "You have had so too much to drink at this point, I am cuttin' you off", she drinks a shot twice between shots.
All The Way - S6-E6
Continuity mistake: When a vampire kicks through a car window trying to hit Buffy, some shards are still standing in the window frame. The angle changes, and the shards are gone. (00:37:00)
All The Way - S6-E6
Continuity mistake: After Spike has fought with the vampire claiming to be a rebel and he is re-loading his cross bow, he is tackled by another vampire and you can hear the sound of the cross bow firing, but as he falls you can see the arrow is still loaded.
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 ★