Continuity mistake: Near the end before Val throws the last bomb,. He twirls the fuse leaving a stub left, which Rhonda lights. Val throws the bomb, and the fuse has grown a few inches. (02:00:00)
Continuity mistake: When the trailer is being dragged by the bulldozer, the wheels rotate. The trailer would need an air hookup to make it happen, otherwise, the tires won't rotate.
Other mistake: Once Earl stops the CAT at Burt and Heather's house, Val is standing on its roof directly above Earl. Val is looking and talking straight at them. The graboids shake the CAT, Earl drives it forward quite a bit (take notice just how far), but he looks up to tell Burt to hurry but he and Val are still facing in the same direction. They should be facing backward due to the distance they had to move up. Also, you'll notice that Burt is right in line with the trailer as he throws most of his gear. (01:14:30 - 01:15:30)
Continuity mistake: When Burt and Heather are fighting the graboid in their basement, shortly after Heather yells "Magazine!", one of the large revolvers between them falls off the rack but is replaced in the next shot.
Factual error: When Val is talking to Burt on the CB radio and desperately trying to tell him to get out of his basement, Burt is using a handheld CB. After Val's very last transmission, Burt is now holding a rifle, not the CB. When the Graboid crashes through Burt's basement wall, we hear him say over Val's CB, "Jesus Chr..." his transmission was cut off. First of all, Burt wasn't holding the CB so he wasn't transmitting at the time. Second, there are portable CBs that you can lock the PTT button for extended transmissions (I owned one), but that wasn't the case here. Finally, even if by some chance Burt accidentally did lock the PTT button before putting it down, it wouldn't have cut off. The Graboid broke through away from where Burt was standing and talking and couldn't affect the CB. It was done for dramatic effect of the scene. (00:58:30)
Suggested correction: Could be he put the CB down on the PTT button (it's a rather large one) and it stopped transmitting when the tremors caused it to flip off it.
Visible crew/equipment: As the camera pans up to the roof of Bert's house, a film crew member is reflected in the window.
Revealing mistake: When the last explosion happens after Val tosses it, what looks like detonating wire coming off to the left is visible for a few frames.
