Continuity mistake: When Rita is being held by Barney in the cabin, she wipes the mud from her face with a white towel. In subsequent shots, her face goes from completely clean to streaked with smears of mud.
Continuity mistake: After Jeff has kicked and punched Barney, he is lying on the ground and blood is covering his mouth and nose and is staining his blazer. When he gets up, the blood patterns have changed and his blazer is no longer stained.
Plot hole: Just after Rita rescues Jeff, Diane's grave is seen close to where Jeff was buried alive. Even though Diane's been dead for several years, her make-shift grave site looks like it was freshly dug. There are no fallen leaves or other debris on top, no new vegetation (moss, grass, weeds, etc.) of any type growing on it, nor has the mound of dirt settled, shifted, or been affected by the weather.
Continuity mistake: When Barney first sees Sandra Bullock, he's wearing a cast in front of the store. Later in movie, they show him meeting her at a vending machine without a cast.
Suggested correction: Barney threw the cast away (into the restroom trash container) after he screwed things up with the oriental lady that was going to hot wire his car, and he accidentally takes in some of the chloroforms' fumes.
Continuity mistake: While Rita is being held by Barney inside the cabin, she looks outside the open door and sees the mound of dirt where Jeff has been buried alive, just a few feet beyond the porch. When she escapes, she has to run a long ways through the brush to get to where Jeff is.