Other mistake: While Dennis is editing one of the video tapes, there's one on a table labeled "89" even though the film takes place in 1988.
Revealing mistake: While driving the Mercedes to the house of grandma, the gauges on the dashboard show speed is zero and the engine is cold.
Continuity mistake: In the first PA, Katie says that the "ghost" was in front of her bed, however we never see it in PA3.
Factual error: Julie mentions the time when someone saw the Virgin Mary on their toast. However, the famous piece of toast happened in 1994, six years after the events of this movie take place.
Plot hole: At the end of this movie, (1988) Kristi and Katie's mother died. In the first Paranormal Activity (2006), when the psychic is visiting he says it feeds off negative energy, and Micha says "I guess we can't have your mother over anymore."
Factual error: During the sleepover in the tent Dennis gives the girls M&Ms to snack on. If you look closely you can see one of the girls eating a blue M&M. These didn't hit the market until around 1995, a full 7 years after this movie takes place.
Deliberate mistake: The film is presented in a high definition raw footage format, which was not available for handheld cameras in 1988.
Factual error: During some of the scenes which take place during 1988, the two little girls are seen playing with a toy killer whale. This whale has three distinctive black marks on its 'chin,' which means it is a Free Willy toy. "Free Willy" didn't come out until 1993.
