Revealing mistake: Watch the scene where they're headbanging and the tape keeps going out. You can see where they splice the scene in because the trees change in the background instantly.
Continuity mistake: After Spade gets foamed, in the scenes to follow, the foam stains change many times, in addition, he has his coat on, then off, then on again in different seems, and the coat never seems to have any foam either.
Revealing mistake: After the roof blows off the cabin, the hail starts falling inside the cabin. It is fairly obvious that the hail is just being poured onto the cabin. Its most noticeable just after the hail starts falling on the cabin, there is a shot taken from inside the cabin you can tell by the night sky and some of the trees outside that there is no hail in the distance.
Continuity mistake: When the boulder is coming down, the front door is open. When we get a shot of the front of the cabin, the door is now closed. However, the doorknob switches from being on the left to being on the right. We also see there is nothing hanging from the porch roof. Before Mike and Steve crash through, we see the front again and the doorknob is back to the left and there's a metal star hanging from the porch roof.
Continuity mistake: When the boulder hits the cabin and Mike falls out the front door, he's rolling, almost off the door, and on his side, with his back close to the rocks. There also is nothing on the back of the door. When it cuts to the close up, Mike is now face down on the door completely, with a dartboard on the door.
Continuity mistake: Near the end of the movie, while at the Governor's mansion, Drake Savage (played by Gary Busey) is in a tree with a rocket launcher. He jumps out of the tree and lands without the rocket launcher. In the next scene, he jumps onto the stage and he has the rocket launcher, which he left in the tree.
Continuity mistake: When Mike is playing football on the field, he scores a touchdown, and throws the football down. Then it cuts away to the kids complaining, then back to Mike, and the lost football is in his hand. It cuts to a larger view of the scene, and where's the football? The camera cuts away again, and then back to Mike and his team. The football is once again in Mike's hand.
Continuity mistake: When Governor Tracy is chopping down the tree, we see the pre-made cuts (that are suppose to be there). After her 2nd chop the shot changes to her family, but when it goes back to her, there's a new notch in the tree and it's not from her chopping as we don't hear her chopping. When it cuts to the tree the final time, after she says "don't let anyone tell you your job is easy", there are more chop marks that aren't from her.