Factual error: When the doctors are operating on Virgil's eyes, you see his right eye closed as if he were sleeping normally. If they hadn't already operated on it, it would have been taped shut. If they had operated on it, it would have been covered with gauze which would be taped on his face.
Character mistake: When Amy goes to Virgil's house to apologize, Virgil tells Amy that the tree is exactly 14 steps away. However he then leads her there by taking 17 steps.