Continuity mistake: While breaking down the bathroom door with the axe, Jack repeatedly strikes and damages the right hand panel, but as he turns away from the door (when he hears the snow-cat) both left and right panels have been damaged.
Continuity mistake: When the windows on Nick's truck are smashed, Elizabeth has protective gloves on when she covers her face from the glass, they are then gone when the truck comes to a halt.
Continuity mistake: After Brenda hears a noise, she puts her book down next to the candle, and walks to the door. When she gets to the door, the book is now by the opposite side of the candle. (00:52:50)
Continuity mistake: The amount of blood on Kate's face decreases between the time she is attacked and discovered. The pattern changes from shot to shot as well. (00:34:15)
Continuity mistake: When the lady anthropologist gets out her teacher's car - you can see in the background the traffic lights changing from green, to amber, to red. When it cuts to another view of her - the traffic lights are on green.
Continuity mistake: Kim is at the kitchen table with her brother Alex. Kim has a necklace on. Kim asks Alex about having a date for the prom and all that is around her neck is a gold chain. The shot then cuts to Alex and then back to Kim and now there is a gold star hanging from her necklace.
Continuity mistake: At the end, the buried biker digs himself out of his grave and shuffles to the smokehouse. When he attacks Farmer Vincent, all the soil and mud stains have vanished from his clothing. Guess he must have stopped off at Zombies-R-Us for some fresh new duds. (01:30:00)
Continuity mistake: The rookie holds at gunpoint the Mad Bomber; in close-up John Lisbon Wood's shoulder is bare, but in the wider angles the shirt is still up and the collar is in place. (00:19:20)
Continuity mistake: Just before Captain Ashland renders Captain Marshall unconscious, Ashland hits Marshall's left hand with the butt of his rifle, bloodying it in the process. When Marshall first comes to, continuity is in place. When they cut back to him, and he rises, it's his right hand that's now bloodied. Shortly thereafter, Marshall is shown running on deck, holding his left arm. When he descends some stairs, the blood is back on his left hand and his right is clean.
Continuity mistake: At the beginning during the house gathering, the toilet seat is up while Arthur is gathering ice from a bag that is in the bathtub. We cut to a shot of Emily and then back to Arthur, where the toilet seat is down. (00:06:40)
Continuity mistake: When John is pushing his car through the snow (with his wife and daughter) you can see the snow on the road is thick and solid. When John enters the phone box the snow suddenly becomes very slushy and muddy. (00:01:30)
Continuity mistake: Kenny must be fast. He's disguised as the female assistant at one point then minutes later he's disguised in the Groucho Marx costume.
Suggested correction: It's not a full costume. Kenny steals the mask and what looks like a small waistcoat (leaving even the hat). It's not implausible that Kenny made a quick change (probably after killing Ed) to formal wear (which isn't what Ed was wearing). After Ed's murder, Kenny-as-Ed appears briefly only from the waist up (showing only the stolen mask and waistcoat), and then doesn't appear again for quite a few minutes, more than enough time to change to the formal wear.