Other mistake: When Robin Wood is burying Jonathan, Jonathan's face flinches when the first heap of dirt lands on his legs.
Continuity mistake: Towards the end of the episode, when Buffy lands on the school bus she's wearing pointed toe pink shoes, but in the next shot where she's jumping off the bus roof, she's wearing brown Timberlake boots. (00:39:11 - 00:39:40)
Continuity mistake: Towards the end of the episode, during Buffy's fight with the Turok-Han, at the construction location, her shoes are very obviously some sort of practical flat shoe, but during her speech afterwards, she is wearing fashion boots with heels.
Storyteller - S7-E16
Continuity mistake: There is a shot where a girl is turning invisible, and when the camera switches to Buffy slapping her, she is fully visible, until it turns back and she is slowly becoming visible again.
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".
Visible crew/equipment: When the 4 Scoobs meet in the hallway for the revolving shot, just as the camera starts to pan over you can see someone casually walk down the hall into frame behind Xander's left shoulder, as the camera starts to revolve you can the person is now crouching in the shadow behind Giles. It appears to be a crew member that accidentally walked into shot at the wrong moment and hid quickly.
Continuity mistake: In many historical flashbacks, most notably Spike's and Anya's, hair and wigs differ greatly from previous flashbacks or episodes. The director even discusses it during the commentary on Lies My Parents Told Me, saying that he doesn't understand why the wigs aren't consistent.
Continuity mistake: Anya's hair changes from straight in the previous episode to curled in this one, even though it is set directly after.
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)
Chosen answer: He had larangitis and because of the shooting specifications they had to have him shoot the scene with a bad throat, they then re-recorded his lines and dubbed them. At various points during the scene and indeed the episode you can see him touch his throat or rub it.