Welcome To The Hellmouth (1) - S1-E1
Audio problem: When Buffy meets Angel, when she says the line "What I want is to be left alone!" and Angel replies "You really think that's an option anymore?" pay attention. Buffy's last few words don't quite match her lip movements, and Angel's lips don't seem to be moving at all for his line. The audio looping is a little sloppy. This is better seen in the brighter HD remaster, but is also noticeable in the original, darker standard definition master.
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