Continuity mistake: At home Buffy helps her mother open a crate. She tears off the cover and leaves it hanging by the side. Next shot the lid is back on. Not nailed anymore of course, but there was no time to put it back on.
Visible crew/equipment: When Catherine and Amy get switched back to their original selves, Catherine takes the fire axe that Amy is holding by using her powers. The wire used to pull the fire axe towards her as Amy holds it up and says "Mom! Please!" is visible.
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