When Alex is at the breakfast table and her dad is in the kitchen stomping out the burning toast, the blinds over the sink are clearly open as sunlight is shining through. However, right after Dr. Wallace leaves the room to get dressed and Alex steps in to clean up the mess the blinds are suddenly closed without either having touched them.
When Bob the security guard is impaled, in the first shot, the spear enters his chest. In the next, it is stuck in his abdomen.