Continuity mistake: When Jason approaches the RV with Cort and Nikki inside, we can see that the vent on the roof (above the front of the RV) is wide open. It is still open when Cort starts driving away. In the next scene when the RV is driving down the road, and after it flips over, the vent is now closed.
Continuity mistake: When Megan and Tommy drive up on the roadblock, Officers Pappas and Thornton chase after them. Notice the precipitation on the windshields of the police cars, and Megan's car. Seconds later when Officer Pappas is on the radio with the Sheriff, his windshield is dry, without any rain drops on it at all.
Continuity mistake: During the scene where Jason kills Court while Court is driving the motorhome, watch as Jason removes the knife from a sheath on his right side to kill Court. Then, the motorhome crashes and Jason exits. When Jason exits and stands on the motorhome, you can see the same exact knife in the sheath on his right side again.
Continuity mistake: The sheriff shoots Jason in the head with his revolver and makes a hole by Jason's right eye. Jason pulls Tommy underwater and begins to choke him and Tommy passes out. There is a close up of Jason's face and the bullet hole is now gone. When Megan tries to save Tommy she cuts Jason's throat with the boat propeller and the bullet hole is visible again on Jason's mask.