Stupidity: When Liz sees the dead deer blocking her lane, instead of merely going around it (using the opposing lane on a rural road without jeopardizing her safety), she exits her vehicle - leaving her three-year-old daughter unattended in the back seat - to "look" at the deer. This furthers the plot by giving the "werewolf" opportunity to attack and kill her... as well as her daughter Miley. (00:42:35)
Stupidity: If Leo wants to kill his son's killer at any cost and no matter what happens, he should've gone directly to his House when the purge starts.
Suggested correction: He absolutely is headed there, but we see at least one incident where his path is blocked due to people out purging, and he needs to turn around. That detour caused him to go a different route, which led him to the mother and daughter. We even see him struggling with the decision on whether or not to help them. He decides to do so, and the rest of the movie unfolds as we see, but there is no mistake.
Stupidity: Charlie set her mom's blouse sleeves on fire and mom/Vicky just stood in the same spot, holding her arms (burning sleeves) out in front of her until Andy came and smothered the flames with a blanket. Even children know to "drop and roll" or put fire out by smothering it. (00:22:56)
Stupidity: The marble somehow got under Don's skin at the bottom of his leg and was moving up the length of his body. Instead of heading off the marble in order to intercept and stop it from continuing up his leg, Don got a knife/box cutter and jabbed it into his skin near the bottom of his leg and trailed the marble, causing a long gash that served no purpose (other than creating a lot of blood and making a gory scene). The marble eventually exited his body via his eye. (01:04:40)
Stupidity: I won't begrudge Father Lamont for instinctively grabbing for the first thing in reach to try to smother the box on fire (even if it is a pair of wooden crutches), but you'd think at some point he'd notice that he's just spreading the fire and making it much, much worse, but he keeps at it until the doctor finally returns with the extinguisher.
Stupidity: Near the end, Sydney Wells and Paul Faulkner try to rescue a little 10-year-old girl who is trapped in the recreational vehicle. Sydney is banging on the door from the outside while the little girl is banging on the door from the inside. Paul then smashes out the door window, reaches inside and easily releases the door latch in one move. So, a 10-year-old girl was "trapped" because she couldn't simply open a door latch? Stupid.
Stupidity: Becky possessed the mysterious key that the four neo-Nazi prison escapees were at the lake house to retrieve. Becky didn't know what the key was for, so did not have a vested interest in it. By first denying that she knew where the key was and later refusing to give it to Dominick, her father was killed. Had Becky simply handed over the key when Dominick asked for it, it is possible no-one would have been hurt/ killed. Becky keeping the key with no importance to her served to further the plot.
Stupidity: Possessed child Nicholas made the cross from a necklace pierce Fr Louis in the neck, causing blood to gush out. Fr Peter yelled, "Fr Louis, Fr Louis" as Fr Louis tried to pull out the cross. No one else present rushed over to try to help stop the bleeding or assist him. Fr Louis' sash could have been used around his neck to apply direct pressure to the wound. (Although it might have been obvious that it was a fatal wound to the neck, someone should have at least tried to help). (00:07:15)
Stupidity: Jake throws Derek overboard to distract the piranha, then swims under the boat and doesn't get attacked, so why couldn't he just go downstairs the normal way and have Kelly swim over to him? They could have escaped a lot more easily.
Stupidity: Dr. Emma Collins and Shaw were in the water with Sally the Great White Shark. Emma put her right hand over Sally's nose and pushed her back. Sally swam forward and Emma pointed her index finger at Sally's nose then pushed her back again. Emma told Shaw, "If you stay calm and redirect" and "Don't try this at home" before Sally pushed Emma with her nose on Emma's stomach and rammed her into an underwater object. Emma was the instigator, goading a Great White Shark. Emma could have been killed. (00:05:10)
Stupidity: Crystal knows she is being hunted and in a very dangerous life-threatening situation yet, after she kills "Ma and Pops" in their Main Street Market, she grabs only a few shotgun shells out of the open box instead of taking all of them or as many as she could find. Also, she walks some distance to the store but did not take anything to drink or eat. (00:27:00 - 00:27:55)
Stupidity: This lady lives in the United States, she obviously doesn't have a criminal record, she can go buy a handgun or rifle, heck she can buy a handgun and rifle and extra magazines and ammo to defend herself, but she chooses golf clubs and baseball bats and mace. (00:00:01 - 01:20:00)
