When Dr. Harding's nose bleeds, the amount of blood switches through the shots.
David says in his childhood home there are 10 windows; 11 if you count the star in the front door. When Dr. Harding drives to his childhood home, 12 windows are visible, and that is not counting however many there are on the unseen side of the house.
Cara says that Adam was diagnosed as having "multiple personality syndrome" by her father, when its correct name is dissociative identity disorder.