Goofs

When Mrs. Mandrakis shows Jill the phone list on the refrigerator, "Rosa Ramirez" is misspelled and has extra letters. About 10 minutes later Jill dials Rosa's number and the correct spelling is shown.

When Jill's friend leaves the Mandrakis' house after sneaking in through the garage, Jill sets the alarm; later she opens and closes the door repeatedly without triggering the alarm.

Jill hears a noise downstairs and quickly takes off the gold necklace she was wearing before investigating. She also put on Mrs. Mandrakis' rings when she went into her bedroom in addition to the necklace, but she doesn't remove them before heading downstairs, and they're gone when the scene cuts to her in the living room.

When Jill discovers her friend's body on the bathroom floor, the friend's left arm is draped over her torso. The camera cuts to Jill reacting, then cuts to an aerial shot of the bathroom as Jill runs out, showing the friend's body on the floor, with her left arm resting alongside her body.

When Tiffany is in her car trying to leave the house, the clock in it reads 1:18. It's just after 10 when Jill gets the call that the sinister calls are coming from inside the house.

When escaping, Tiffany gets into a Toyota Matrix, but when she goes to lock the doors, the locks are not the Toyota make.

Actress Madeline Carroll's name is spelled wrong in the opening credits as "Madeleine Carroll" though her name is spelled correctly in the end credits.

In the scene where Jill is in the Guest House and answers the phone, when she hangs it up we get a look at the screen on it. You can clearly see that the battery is almost empty, but she just picked it up off the charging station a minute ago.

About halfway through, Jill calls her friend at the bonfire, but the static on the cellphone is nothing like the sounds expected from a real cellphone when reception is poor. Also, the intercept she receives in subsequent attempts to call her friend, first includes chimes initiated by the old Bell system decades ago for landline phones. Cellphone companies use neither those chimes nor the wording used in this film. No recording since the 1990s would say "I'm sorry, the person you're trying to reach is out of range."

When the kids run away from the stranger, the girl screams but her mouth doesn't move.

Every time the cat runs across the floor, a skittering sound effect is added in, as if it were a dog. Unlike dogs, cats have retractable claws, and walk silently.

Tiffany and her red Toyota Matrix get inside the locked gate to the Mandrakis residence without a code or being buzzed in to sneak in and scare Jill.