Revealing mistake: Just as Jacob enters Bella's room through the window, a stunt prop - white band on his right wrist - is briefly visible.
Suggested correction: There is nothing on his hand if you watch frame by frame.
Visible crew/equipment: In the scene when Edward left Bella, when Bella is running after Edward, you can see the shadow of a crew member briefly on the tree.
Suggested correction: This was Bella's shadow.
Other mistake: Bella just got back from the meadow with Laurent. She is describing what she saw to her Father and Harry. Notice that every time she talks there is a grey/black line across her chest. It is obviously not a necklace or her hair. But then her Father says "Wolves, You saw them?" Now, everytime the camera pans onto her, the grey/black line is gone.
Suggested correction: It is absolutely obviously her hair.