Stupidity: The protagonist with her kid stops a car with two guys, in the middle of the night in an isolated country road. Both the adult and the kid scream that a dangerous maniac is chasing them. So naturally, the two guys (who do believe them, it's not that they are being dismissive) offer them some hot coffee, and they drink it right there in the middle of the street, not dialling for help, getting in the car to drive away or anything, because that's what normal people do when you tell them a serial killer is nearby; stop for a hot cuppa.
Stupidity: Alex, a contract killer, went to the hospital to kill a patient. After parking in the hospital garage, Alex put his car keys under the sun visor, risking the possibility that his car could be stolen. When Alex returned to his vehicle, the keys were not there. A professional or expert assassin should take precautions to assure his getaway car will be there and keep his keys on him. (00:01:45 - 00:04:30)
Stupidity: After eating the bird, why didn't Becky send her phone down inside the bird, but instead climbed down to put her phone inside Hunter's body?
Stupidity: As soon as Bundy got into the building (instead of when he was still outside), Kaminsky asked him for a "camera check." Bundy had a yellow button with a big star in the center pinned to his jacket's right lapel. Bundy put some fingers next to the button and raised his lapel with the others, making it obvious he was wearing a camera. When Manson got into the lobby (area likely to be under video surveillance), Reese (who saw Bundy and Manson outside) came into the building to give them weapons. (00:03:50)
Stupidity: Don told Allen he'd have to wear a blindfold to his house because he didn't want Allen to know where he lived. Instead of having Allen ride in the cab where he could monitor him to make sure he didn't remove the blindfold, Don made Allen ride in the truck's bed (where Allen did lower the blindfold to use his cell phone). (00:14:24 - 00:17:00)
Stupidity: After the cloth was lit, the "Santa" could have easily thrown the Molotov Cocktail far enough to ignite the Christmas tree but, instead, casually walked to get closer (within several feet) before tossing it. This may have been for dramatic purposes, but carrying a lit rag (part of a Molotov Cocktail) unnecessarily increases the risk of getting a burn injury (which can be quite serious/painful). (00:02:35)
Stupidity: How did Elvis not know that Gary wasn't in his house? Gary said he just put 2 bullets in Elvis' poster. And why wouldn't his wife tell Elvis they weren't at home? And what happened to the cops who busted into his home and found nobody there? Why wouldn't they go to the station?
Stupidity: David was seriously injured by Olivia a few times (e.g, hit by her car and on the head with a baseball bat). When Olivia went into the bedroom, David was able to knock over his chair, get a knife off the floor, and free himself from being duct-taped to the chair. David took the car keys but left the knife on the floor, even though he was weak and vulnerable and Olivia had previously chased and caught him. When David returned to the cabin, Olivia came in with the knife and keys. (01:02:55 - 01:09:49)
Stupidity: Wes is characterized as one of the more careful characters early on, buying both a stun gun and pepper spray. When he comes home after the meeting where the dangers of Ghostface were further laid out, he proceeds to set both his weapons down and takes a shower after his mom tells him he'll be alone in the house, which is exactly how Tara and countless victims of previous sprees were attacked. The fact he even lived through his shower is lucky enough.
Stupidity: After Danny kills Kat on the sidewalk, he just stands there with Rory while the other gang members flee to their vehicles. William comes running out of the Mexican restaurant and Rory tells Danny, "We gotta go, brother. Now." Rory sees William and gets into the vehicle without getting Danny to go with him. The gang drives away with Rory watching out the window as William tackles and fights with Danny. Rory and the rest of the violent gang left behind someone who just passed the initiation. (00:07:10 - 00:07:40)
