Continuity mistake: When John and Maggie are at the old school, there is a teacher talking to a class which isn't really there. The teacher stands by the left side of the blackboard, which has large crosses drawn on it, in rows. It cuts to a closeup and the crosses are now smaller and more scattered.
Continuity mistake: John opens the window to find out the house is falling, and a large object goes flying through the window next to the bed, smashing out all the glass and all the wooden frames. Seconds later all the wooden frames are now repaired, however all the glass is still missing.