Visible crew/equipment: When Willow and Tara are talking about Dawn, just as Willow turns around from hanging her picture to say "help?", a boom mike drops in from the top of the screen. (00:18:35)
Audio problem: When Joyce is about to leave for the pre-show, we hear Xander say "Have fun, but not too much fun", but his lips never move.
Answer: She has superpowers, ergo fast movement. The reason she outruns him so easily in "Touched" is that she stops trying to actually fight him and just dodges instead.
Shay