The boys are in "The twilight time between school ending and when your parents come home." There is bright daylight outside. Hal bursts in and we see daylight through a window behind him. He takes the boys outside where it is night time and wall-mounted lamps are lit.
Near the safe, Craig confesses to Lois that he loves her. During her response, the shape of her fringe/the fall of her hair changes.
As Malcolm is talking to the camera, Reese is in the background, supposedly sawing a book in half. But his arm is moving around too much, showing no resistance, and looking down at the saw, it can be seen that it is beside the book, not going through it. The camera changes and now Reese is seen actually sawing the book.