Continuity mistake: After Carol goes through her mom's body, a huge wind sweeps away the living room. The lamp next to the TV falls down, but a second later it's facing upwards again.
Continuity mistake: The reddish brown goo on Robbie's face after he's almost eaten by the tree varies between camera shots.
Continuity mistake: After Carol Ann's been abducted, her family walks upstairs and places one mattress on top of another. A few seconds later they are arranged in a different way.
Continuity mistake: When Diane and Carol Anne are lying in the bathtub towards the end, Carol Anne's hair and hand position change drastically between the wide shot and the closeup.
Continuity mistake: Right after JoBeth Williams and Craig T Nelson joke with Dr. Lesh about not showing the tapes of their haunting on "60 Minutes" or "That's Incredible", JoBeth walks to the table with Dr. Lesh's flask in her hand. As she walks from the sink, there's a silver cap on it. When she gets to the table, the cap is gone. She couldn't have removed it out of sight, she had a coffee cup in her other hand.
Continuity mistake: When Diane and Carol are in the tub, the amount of red slime on Diane's forehead, and foam on Steven's hand increases or decreases between shots.
Continuity mistake: The first night the ghosts come out of the TV, before Carol Ann wakes up, there's a pillow on the background laying on the floor by a basket. When she walks towards the TV the pillow is standing upright by the basket.
Continuity mistake: Diane places the liquor flask upside down on the table, but a frame later it has turned 180ยบ.
Continuity mistake: Returning from the pool, Diane enters the kids' bedroom and starts to fly, covering the door with mud. A second later the door is clean, only to dirty itself in the following shots.
Continuity mistake: When Robbie leaves in a taxi, in the close-up Steve is massaging Diane, in the wide angle he is just standing behind. This keeps swapping back and forth.
Continuity mistake: When Carol Ann is about to be abducted, sometimes she is suspended horizontally over the bed, others diagonally.
Continuity mistake: The back window of Robbie's cab goes from being up to halfway down from shot to shot.
Continuity mistake: After the credits, the position and amount of beer cans around the fallen bicycle changes between shots.
Continuity mistake: The clown puts his hand around Robbie's throat, but a frame later disappears.
Continuity mistake: When Carol Anne goes to the TV in the parents' bedroom the first time, the clock on the TV changes from 2:38, 2:58, 2:38 and then back to 2:53 with each camera angle change.
Continuity mistake: The piece of licorice that Carol Anne puts into the cigar box with the dead parakeet "for when he's hungry" appears to be close to 6 inches long when she's placing it in the box but no more than a couple of inches long when it's shown in the box a few moments later. (00:10:10)
Continuity mistake: Just before the house starts to implode, Teague is backing away from it and as he does so, he passes a couple of white garbage bags on the sidewalk and backs into the street. In the next shot, taken from across the street showing bystanders being blown backwards, Teague is visible in the background; he's back on the sidewalk tripping backwards over the same bags he safely passed moments before. (01:48:10)
Continuity mistake: As the Freeling family is escaping through the side of their house, you will notice that Diane is holding a doll that looks like Carol Anne.
Continuity mistake: Toward the end, when Diane and the kids are trying to escape, they start into the kitchen only to see 2 coffins come up through the floor. The initial shot shows the coffins quickly shooting up to almost the same height and then stopping, but in the next shot, in which the coffin on the right opens, the one on the left is a couple of feet lower and is still slowly rising.
Continuity mistake: When Diane is about to dye her hair, the shampoo bottle changes positions between shots.
Answer: It seems that the majority of the activity was focusing in on the Freeling house exclusively. It's not fully explained why they were the only house affected, but there are a number of possibilities. Possibly because it's where the highest concentration of spirits were at unrest. Possibly because it could be inferred that the Freelings moved in first given Steven was involved with the company that built the community, and thus they became the first targets. And possibly because they were trying to get to Carol-Anne since she was an easy target.
Also, it is mentioned in the movie that Carol Anne was actually born in the house. That likely caused everything to focus on her.
It was not meant that Carol Anne was literally born inside the house, just while the family was living there. It was just a casual colloquial expression Steven's boss made.
raywest ★