When Lisa is scared and goes back out through the little door the key she used to enter is missing, and when she pushes the door back open the key re-appears in the lock.
In the attic, there are two different box versions of Clue. One version in the opening wide shot, a different version in the close-up when Lisa grabs the Ouija board.
When Lisa moves the washer over to look inside the small red door behind it, there are no connections for the water for the washer.
One of the old newspapers reporting the missing girls is dated Thursday, April 30, 1955. April 30 that year fell on Saturday.
In the scrapbook called "Photographs" that Lisa discovers hidden under the floor in her bedroom, the third column about Frances Nichols in the first article repeats the same content as that in the first column. In the subsequent article about the second missing girl there are numerous repetitions in its content throughout. Later, the same story of Frances Nichols is shown typed in the article adjacent to the picture of a different missing girl.
When Lisa watches the "Moving Day" video, her little brother is wearing an Edmonton Oilers sweater, but this is the style sweater the Oilers wore at the time the movie was made in 2012, not the style they wore in 1984. The NHL crest at the base of the collar gives away that it is not a 1980s sweater.
Robert is shown playing the Atari 2600 version of Pac-Man, however the game sounds played are from the arcade version of the game and not the Atari 2600 version.