Continuity mistake: When they are eating at the dinner table you can see that there is no rug, but later when Jane was looking out the window after the first time she was being video taped you can see that there is a rug under the table. (00:06:59)
Audio problem: At the end of the scene when Carolyn cannot sell the house, she closes the blinds and then walks across a bare hardwood floor in heels...Do you hear any noise? I don't...it would have been very echo-y in that room with no furniture or carpeting! (00:13:40)
Continuity mistake: In the beginning of the movie, after "mentalboy" has filmed Lester and Janey in the kitchen, Lester looks out the window. The kitchen is lit up, and it is very dark outside. This would naturally produce a reflection in the window, making looking outside impossible. There is no reflection. (00:10:00)
Continuity mistake: When Carolyn calls Lester and Jane out whilst honking the horn, the shot changes from her to the house several times. Each time the shot is facing the house the side mirror is flapped in and while facing her it isn't. Additionally, in the same scene when Lester comes out, his briefcase opens and his cellphone falls out toward the car out of reach, when he picks it up again it's right next to him.