Continuity mistake: When Buffy is hitting the punching bag near the end of the episode and Riley comes in she has bandages wrapped around both her hands but in the close up shot there is only a bandage on her left hand.
Continuity mistake: After Riley stakes Spike and Spike decides to drink, he is shown opening the bottle. The camera shows Riley and then goes back to Spike. Spike is holding the bottle, lid still on, then he goes to open it again.
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