Continuity mistake: In the opening scene, the wind has blown a tree down toward the house, which is away from the lake. In a following scene the tree has blown down on the boat house, which is toward the lake. (00:01:20)
Continuity mistake: When Brent thanks David for helping him out by taking him to the store, David is holding his shopping list with both hands. In the next shot David is holding his right hand up by the shelves. (00:08:55)
Continuity mistake: When the tentacle monster rips out a chunk of Norm's chest, a large spray of blood splashes on his right-side jaw and cheek. In every subsequent shot of him, this blood is gone and his jaws are completely clean. (00:26:30)
Continuity mistake: When Norm is dragged out by the monster, there is no blood trail however after they close the door, there is. (00:26:35)
Continuity mistake: Once David has dealt with the monster in the store room his shirt is completely soaked with sweat. When he returns to the main shopping area, the sweat stains are much smaller. (00:32:00)
Continuity mistake: When Brent and Jim are arguing just after Norm was killed, the cut on Jim's lip keeps disappearing and reappearing. (00:36:00)
Continuity mistake: When Jessop gets lynched, his shirt collar is tucked into his jacket in some shots and not others. (01:32:00)
Continuity mistake: When Private Jessup is thrown out, he walks up to the door and places his bloody hand on the glass door. When the monsters pulls him away, the position of the blood stain on the glass doesn't match where he had his hand in the previous shot. (01:34:55)
Continuity mistake: The hand print that is left on the door changes between shots. In one the blood is fairly light and in the next its a lot darker. (01:35:00)
Continuity mistake: Near the end of the film when the five of them are in the car, they stop to watch a giant monster walk past, shaking the car. When we see the monster again it is walking away from them, but the telephone cables are still erect - it is clear that these would have been knocked down by the monster. (01:48:20 - 01:48:55)
Suggested correction: It actually does knock down some of the poles and cables. It just doesn't knock them all down. The ones you see still standing as it walked away are a fair distance away from where it was walking... hence, they still stand.
