There is no way this girl could know everything that went on, even when she wasn't around to witness things. I know they tried to explain it away but it still doesn't make sense.
I kind of got drawn into the mystery aspect of the movie of who the killer is....even though I was pretty sure from the beginning....but there were enough red herrings to make me doubt that the people who made the film might not pull a fast one on me. The final reveal is the Usual kind of thing that makes you Suspect that the writers think they're pulling off a great twist when really they're just half-assing the ending of a much better movie. Still though it did keep my attention.
What ever happened to the dog?