Hair of the Dog (S01E03) plot hole

Link: http://www.imdb.com/title/tt0951629/

Just started watching these.

In this episode, the killer takes a piece of scalp and the canines from each werewolf killed. We learn this is so they can cast a spell to remove their lycanthropic curse... except that as Bob claims, "Kill nine in the line, release is thine" (or something like that). IOW, no spell necessary, no body parts, just kill nine in your bloodline.

[Which, given the surliness of werewolves, could make for an unfortunate de-lycanthroping for a particularly feisty family-fighter who's bad with numbers... "Oh, *beep* that must have been my 9th were-cousin! Crap!"]

In fact, that's exactly what happens: the villain kills her lover by mistake, after making him by mistake, and POOF! she's mortal again. No scalping, no fangs needed... unless they were on her person, and him being present was enough.

Mostly, it just feels like a plot hole.