Revealing mistake: In the scene where Drusilla and the new reformed Angelus are in the shopping mall and they got blown over the side after Buffy fires the grenade launcher at the Judge, you can tell that it was Mike Mass and not David Boreanaz that got blown over the side.
Revealing mistake: Drusilla's reflection can be seen in the metal part of what appears to be the base of a shopping mall map just as she's getting up after the Judge has been blown up.
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