Continuity mistake: When Buffy decides to leave again and goes to her room to pack, her door is three quarters shut when she goes in, half open when Willow comes in and almost fully open when Joyce comes in. At no point does anybody touch this door.
Continuity mistake: In episode 'Anne', when fighting the hell dimension demons Buffy's shoes change from trainers to plain pumps in different shots.
Continuity mistake: When Pat puts on the demon mask and punches Buffy into the bedroom door, she hits the door with her back and then falls to the floor on her face. In the immediate shot she hits the floor again, but this time on her back.
Continuity mistake: The time on the clock, when Buffy spots Jonathan, changes dramatically between shots.
Continuity mistake: Near the start of 'The Wish', the scene where Cordelia is talking to the Cordettes and meets Anya. During the close-ups of Harmony, Anya is standing to camera right of the brunette Cordette behind her. A few seconds later when the shot is further away Anya is standing camera left of the Cordette. (00:05:40)
Revelations - S3-E7
Continuity mistake: When the female watcher is being destroyed after Buffy cuts off her arm. Her sleeve is empty, which is not possible, as Buffy could not have removed the arm but not the sleeve. Also the arm on the floor is removed at the elbow, but the watcher has lost the entire arm in a previous shot.
Continuity mistake: When Buffy is walking forwards through Angel's dust in 'The Wish' there's a vampire running towards her, only a few steps behind. Then there's a shot of her walking forwards taken from another angle, then when we can see behind her again the same vampire hasn't moved forwards at all, he's still running from 3 steps behind her. (00:41:25)
Lover's Walk - S3-E8
Continuity mistake: In the episode Lover's Walk, when Spike is threatening Willow at the factory, in the long shots Willow's hair is up over her face, and in the close-ups it isn't. The pointed bit of the bottle is at the top or bottom in different shots too. (00:19:20)
Continuity mistake: During season 7 we are told several times that the First cannot take corporeal form, ie. it cannot touch things. However, in its first appearance in the season 3 episode 'Amends', when it manifests as Jenny Calender and runs its fingers through Angel's hair you can see his hair moving underneath her fingers. It wouldn't be able to do this if it weren't corporeal. (00:15:50)
Gingerbread - S3-E11
Continuity mistake: In the previous episode 'Amends', Buffy was sporting a brand new short fringe. In this episode it has grown out. Completely.
Lover's Walk - S3-E8
Continuity mistake: In the scene when Spike was in Buffy's kitchen with Joyce, Buffy keeps him down on the table and grips Spike by the throat. She uses her left hand (in the close shot it is also the left hand) but in the next scene when Angel is also in the kitchen and Spike hits Buffy's hand, she uses her right hand (Spike hits her right hand).
Continuity mistake: In the library, a book in front of Buffy begins to slide off of a stack of books. Change of camera and book is back on top of stack.
Continuity mistake: When Joyce throws the bag with the stray cat into it into the hole, the bag lands with the knot at the top right, and shows no signs of moving. They chat for a few seconds about something to say, then when Buffy starts filling in the hole (with no sound of a moving bag), the bag's now lying with the knot on the left.
Continuity mistake: In 'Graduation Day, Part 1' when Buffy and Faith are fighting Faith falls into a table, knocking all the comics on it onto the floor. In one or two later shots you can see (on the very edge of the screen) that there's still a comic on it. (00:38:20)
Continuity mistake: When Willow hands Giles the pages she stole from the books of ascension, initially the folded side faces to the left, with loose edges of pages to the right, then in the next shot the folded edge is now on the right. (00:36:25)
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 ★