End Of Days - S7-E21
Audio problem: When The First lets Buffy get away with Caleb's scythe, Buffy jumps back up the trap door but we don't hear her touch the ground as she lands.
Get It Done - S7-E15
Audio problem: When The First uses Chloe to mimic Buffy, Chloe's lips don't quite match her words.
Audio problem: When Buffy is about to close the door as she goes into the bathroom, it actually never closes. But we still hear the sound of the door closing. (00:15:20)
Audio problem: When Giles and Anya are talking to the demon, trying to get him to open the portal to Beljoxa's Eye, when you see Anya's face from the side, her lips don't sync up with what she is saying, and sometimes her lips are moving to words when she doesn't have any lines at all.
First Date - S7-E14
Audio problem: In the graveyard scene when Cho-Anne says the Cantonese translation of 'I don't understand what any of you are saying', watch her closely in the shot just before it. She starts to mouth part of the line early, but we don't hear it.
End Of Days - S7-E21
Audio problem: When Faith is in bed and talking with Buffy, she says, 'and no one else can feel it' her lips don't sync with what she's saying.
Audio problem: When Anya comes in from helping the potentials get in the car, she says that Molly is in the trunk. She then says something along the lines of "I'm surprised at how compact Molly is," as she walks away with Willow, but her mouth doesn't move.
Storyteller - S7-E16
Audio problem: After Anya and Xander sleep together again, Anya says "I think, maybe we're really over. Which - it's good, right? I mean, now we can move on." When she says "Which - it's good", her lips don't match what she's saying.
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 ★