Continuity mistake: When Riley's boss says he's giving her extra hours and she's closing, Riley looks down to the side in her close up. When the camera cuts again as he walks away, she's suddenly looking up straight ahead towards him as he walks. (00:08:40)
Continuity mistake: When Fish gets shot in the leg and runs out of ammo, we see him on the monitor still trying to shoot in vain. When it cuts to him, the slide is locked back and we see him release the slide and try to shoot. But in the next shot of him, the slide is once again locked back. Since we know he's out of ammo and he didn't reload or fire the gun, the only way for that to happen is if he manually pulled the slide back, which he didn't have an opportunity to do (not that it would even make sense to do).
Continuity mistake: The children sink into the grain when they fall into the silo however when the monster stands atop the door they are hiding underneath, they don't sink in.
Continuity mistake: At the ballpark, Poole is seated (alone) in the top row, four seats in. There is a large square pillar separating the next section (to the left of the screen). In the lower left-hand corner, a dark-haired man with a mustache can be seen. When the camera returns, the pillar is gone, Poole appears to be in the third (not fourth) seat, and the dark-haired man is seated as high as Poole. (00:39:35)
Continuity mistake: When Bart's dad asks how he got such a beautiful girl, he looks at Bart. The shot cuts to behind him and suddenly he's looking at Shannon again.