(at around 1h 13 mins) When Heidi goes missing, her father finds one of her pink sneakers in the dirt by the truck where she was taken. Fast-forward to her mother trying to push Heidi from below out of the "taxidermy pit of hell", Heidi has both pink sneakers on.
(at around 23 mins) The newspaper obituary from which Mr. Gordy's picture is clipped shows that he lived from 1901 to 1979. However, the TV broadcast about the five male bodies found underground on the property states that Mr. Gordy died in 1978 (at around 1h 1 min).
(at around 54 mins) When Heidi picks up the doll that the ghost placed on the ground, she leaves her teddy bear on the ground, but the bear isn't there when Heidi then runs into the woods a moment later.
According to the dates on the screen, the moon is full on three nights in July over a period of 20 days.
The film is set in 1993, yet all of the character's clothes (those in 1993), hair and makeup are highly anachronistic. They all wear styles that became popular around 2003 and remained popular until the time of filming.
(at around 1 min) The drug she takes, Olanzapine, is the generic form of Zyprexa. The film is set in 1993 and Zyprexa didn't go generic until 2011.