I would have to watch the movie again knowing that the found footage was fake (I was COMPLETELY fooled the entire time btw), but I would guess 85-90% of the footage was filmed by Polley. I mean nearly every shot with the mother was by an actress- and even that scene with the kids teasing Sarah at Sunday dinner was staged.
Rebecca Jenkins, who played the mother, gave one of helluva performance. Honestly I found it to be nomination worthy. Simply brilliant work- and she never got to speak!
I think the interviews were unscripted.
I can't stop thinking about this movie. I want to take Polley out for drinks and ask her a million questions. I bet she'd be a lot of fun too.
Marie: Don't be in such a hurry about that pretty little chippy in Frisco.
Tony: Eh, she's a no chip!