Audio problem: When Sidney comes running to the house and she sees Dewey come out with the knife in his back she screams "Dewey!" but her mouth says "no!" (01:27:23)
Audio problem: When Gale is talking to Kenny the cameraman before she goes off to investigate the abandoned car with Dewey her face is in a close up. She can be clearly heard uttering the forbidden phrase "I'll be right back." However her mouth can clearly be seen saying "keep watching." (01:11:25)
Audio problem: When Gale starts driving away after she hits Randy with the phone, Kenny's body falls on her windshield. At this part the camera pans to a shot overhead and Gale says "Kenny, I'm sorry, but get off my f***ing windshield!". Her mouth is not moving as she says this. (01:26:35)
Audio problem: Gale exits the TV truck telling her cameraman "I'll be right back" to go with the theme of the movie. However, the line is dubbed over and Courteney Cox says something shorter and different. (01:14:25)
Audio problem: At the party, Gale places a portable small camera on top of the TV to spy on the teens there. Later, the teens are watching the Halloween movie on this very TV and talking loudly. The movie is playing with sound when they are watching it. However, when we see Gale and Kenny's perspective as they are watching the feedback, they can hear the teens talking. However, despite the camera sitting right on top of the TV, it doesn't pick up the audio from the movie playingr. This mistake is repeated not long after when Ghostface is sneaking up behind the one teen left behind on the couch who's watching the movie at an even louder volume.
Audio problem: After Sidney and Billy have their fight in the hallway after he's released, the scene cuts to Mr. Himbry reprimanding two students wearing the Ghostface mask. He takes some scissors and starts to cut them up and waves the scissors around. The entire time, the scissors are making very loud, very distracting and unrealistic "SHING" sounds like metal swords sliding against each other in a hallway. These scissors simply would not make such obnoxious sounds with the simple movements he's doing with them. They even make the sound as he's cutting through the mask, which if anything would have muffled the sounds they made even more. (00:44:50)
Audio problem: When Tatum throws the first beer bottle at the killer, she yells out, "F***er," but her mouth doesn't move. (01:04:05)
Audio problem: When Sidney gets in the truck, Kenny tells her "There's a camera in the house" but his mouth barely moved. (01:23:15)
Audio problem: Casey's dad tells his wife to call the police. Meanwhile, he runs upstairs yelling "Casey, are you upstairs?" He reacts to his wife's line turning towards her before she says "Casey, baby?" (the mother does whisper "My God" a moment before he stops and turns too, but it was a whisper, good luck hearing that when he was rushing upstairs and shouting his line). (00:12:10)
Audio problem: When Steve is on the porch and gagged, the killer instructs Casey to turn off the lights. Steve shakes his head and lets out some muffled 'No's. When the lights go out he says one last 'No' but you can still tell he isn't saying it. Even though his mouth is gagged, he makes no body movements to correlate with his shouts like he did before, especially not his jaw. Despite it being dark you can still tell. (00:06:10)
Answer: Characters in horror movies are notorious for not doing the most obvious things. It's most likely that she was scared and not thinking straight at receiving numerous threatening phone calls, particularly when she is threatened after hanging up on the killer.
Manky
Also, when she told the caller that she was "two seconds away from calling the police", his response was that they'd never make it in time. She also knew he was nearby as he made comments that indicated he could see her. She didn't know it was someone that knew her. She's a teenager and scared, so her judgement was clouded. She reached a point where she believed her only chance was to get away from him by either fighting him or getting out and hiding somewhere outside.
dewinela