Continuity mistake: When the girl's face is pushed through the cabin window, her blood runs down the side of the sink. Later on, when the father comes in the cabin the sink is clean with no blood.
Continuity mistake: Clearly a different guy playing Zack in the beginning as he looks to be over six feet tall and has a full head of combed back brown hair. Zack later on looks like he's only 5'5" with receding brown hair.
Continuity mistake: Graham is on the bed as it comes crashing down the stairs. He proceeds to disappear, reappear, disappear in the group shot and then finally reappears once again. (00:26:35)
Continuity mistake: At the pool when Sean and Molly are lying on towels discussing their families there is a shot focused on Molly's face, and she says she has a big family and people refer to them as "The Brady Bunch." In this shot you can see a very distinct blond haired man in the pool behind her. The shot then changes to a wide shot showing both Sean and Molly again and the same distinct blond haired man is now behind them on the other side of the pool. (00:14:54)
Continuity mistake: Many editing mistakes with the 'accidents' including the guy at the weight set, when his ribs crack through his skin. In the following shot all is normal again.