The level of Mr. Herkabe's car window changes during his talk with Malcolm.
When we first see Lionel Herkabe in his car, the driver's window is open (to avoid showing reflections). One second later with a change of camera shot, the window is shown closed.
In an early scene Stevie has a desk in front of his wheelchair. In a later scene he has no desk.
Malcolm joins Reese in the school yard. Initially, the sky is overcast. When Malcolm sits, the yard is in full sunshine.
In the first classroom scene, Stevie's wheelchair is behind a desk. At the end of the class, the desk disappears so that he may wheel straight out of the room.