Continuity mistake: When the members of the brotherhood beat up Mani until he is dead, they pick him up above their heads. The tattoo on his torso appears to be on his right side, whereas in previous and following scenes the tattoo is on his left side. That shot is flipped.
Visible crew/equipment: Toward the end of the movie, right before Fronsac has it out with Jean Francois, he kicks everyone else's butt. There's one shot where he kicks an attacker who proceeds to go flying back. When he hits the ground and the dust and leaves start to settle, you can see the wire leading out of the shot.
Answer: She wasn't really evil. The whole movie is a metaphor for the shockingly bloody French revolution. The fact that (at least towards the beginning) the beast usually only kills women and children is a nod in the direction of the countless innocent (women and children) who were put to death in its course. The healer's daughter is sort of an omnibus of the French peasants' lust for blood. She's not evil, she's just crazy - the mad child of revolution. Sorry for the lengthy explanation, but if one goes into it without knowing, it can be a bit confusing.