Character mistake: Time and time again, Buffy or another of the Scoobies have gone a few metres away from a vampire and talked about them, shouldn't they be able to hear them? Because aren't they supposed to have heightened senses?
Character mistake: In this episode, Buffy says that Drusilla could be alive because they 'never saw her body'. Drusilla is a vampire; if she was dead, there wouldn't be a body to see - as the slayer, Buffy knows this.
Character mistake: When the zombies break into Buffy's house, she stakes one to check if it's a vampire. But she should know full well that it isn't a vampire as they all broke into her house without being invited.
Character mistake: At Riley's party, Willow tells him that Buffy is wearing a halter top when she is in fact wearing a strappy top. Being a girl, and extremely into fashion at this stage in her life after her high school years, she should have known better.
Character mistake: Willow refers to the Tunguska Blast of 1917. However, that event actually occurred in 1908.
Character mistake: At the end, the new manager tells Buffy that the burgers are ground up veggies with rendered beef fat. But earlier in the episode, when Buffy finds the severed finger, it shows chunks of beef being ground up.
Character mistake: Giles picks up the potential slayer Chao-Ahn from Shanghai in Episode 7.12, "Potential". However, when she arrives in Sunnydale (Episode 7.14, "First Date"), the language she speaks is neither Mandarin nor Shanghainese (the two main languages spoken in Shanghai), but Cantonese, which is not widely spoken there. (00:08:55)
Character mistake: When Buffy is looking around the new high school, encountering the first sign of the school being haunted, there is a notice board in one of the corridors entitled "theatre". This is the British spelling. Sunnydale is in America and therefore the word should be spelled "theater".
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 ★