Trivia: The scene in which Buffy attempts to convince customers the hamburgers are made out of people spoofs the infamous climax of the Charlton Heston film Soylent Green.
Trivia: In the season 6 episode "Doublemeat Palace", Buffy has to get a job working at a local fast food joint. The writers went out of their way to make it seem like the most miserable, degrading job ever. After this episode aired, several fast food franchises in real life like Burger King pulled their ads from Buffy in protest.
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