After Jim is struck on the head he falls down the attic stairs getting a lot of dust on his trouser legs. When he gets up the dust is gone.
Looking at Barney's TV control console about 34 minutes in, the word "Horizontal" is misspelled as "Horisontal".
At one point Dana appears to Bainbridge as a ghostly projected image floating above his bed, her white robed arms held wide. But when the scene cuts to Barney shooting the projected image live, Barney's video camera is clearly on a head-and-shoulders close up, with Dana's arms not visible.
When Mrs. Foster is speaking to Jim in the hallway outside his bedroom, the boom mic can be seen in the lower left corner of the frame as Jim walks towards Mrs. Foster.