Continuity mistake: When Bert first realises he has the fever, he crouches beside the car and starts coughing up blood. When he hears the others coming he wipes his mouth, leaving a small trail of blood on his chin, but when he stands up and talks to them the blood is gone and his chin is clean.
Continuity mistake: When Bert returns from shooting, he talks to Jeff and Marcy, when returning his BB gun hangs over his right shoulder. Shot changes and his gun hangs over his left shoulder. When it cuts to the last back closeup of him and as he walks away to the cabin, you can see the gun has jumped to being over his right shoulder between the shots.
Continuity mistake: When the kids are in the shop near the beginning of the film, at the shopkeepers desk is a cardboard box, and next to it are some jars and tins. Between a couple of shots the jars/tins rotate and move position on the desk, and also two or three jars/tins appear then disappear.
Continuity mistake: When the blonde goes to kiss her boyfriend as they are floating on a platform in the lake, she rolls herself off the platform and completely submerges herself underwater. When she comes up for air, it cuts back to her boyfriend looking at her, then back to the blonde who is head above water and her hair is completely dry.
Continuity mistake: When Marcy, Bert, Jeff and Paul are in the cabin talking about the fact that maybe they should prepare their own meals, during the conversation before the scrap between Jeff and Bert, watch Marcy who's sitting on the couch. Between shots she goes from having her hands up in the air, to folded or down in her lap.
Audio problem: In the scene where Marcy tells Paul that he hurt her back (when they had sex) you can hear a clock ticking in the background. But in the scene a few minutes earlier where she talked him into having sex with her, that takes place in the same bedroom, the sound isn't there.
Continuity mistake: When Marcy jumps up in the bath/shower after shaving the flesh off her legs, we see a lot of blood pooled around the wounds on her back when only seconds ago we saw that the wounds were scabby, but not bleeding at all. Not only that, but somehow the blood has managed to spill upwards, reaching several inches above the wounds it came from. Also, when she begins to jump up, she's facing the shower head directly, but when the camera angle changes, she springs up facing towards the bathroom mirror, which is about a 45 degree angle difference in direction.
Factual error: A doctor is seen using a syringe to inoculate the individual with the disease. It is clear that the containment gloves and sleeves he is using are not proper as you can see his skin between the gloves and the sleeve. If this were a real containment unit his entire skin would be covered.