Revealing mistake: There's one bit where we see the shark slamming into a boat and gliding along the side with its mouth open. Not only does the shark's latex mouth bend beneath the snout, narrowing from pressure, but within the mouth you can clearly see yellow hydraulic tanks to open the mouth. (01:22:05)
Visible crew/equipment: Just before Laurie stabs Michael with the knitting needle you can see that one of the window shutters is open and that the wind is ruffling the curtain. When the camera gets closer and the curtain is out of the way you can see the huge fan in the studio being used to simulate the wind outside. (01:19:50)
Factual error: When they are refuelling the helicopter (as a zombie approaches quietly from behind) the actor has put the gas nozzle not into the hole for the gas tank, but into one of the foot-holes that helicopter mechanics use to climb up to the top of the helicopter to do repairs. It doesn't even fit properly. (00:22:55)
Visible crew/equipment: After Matthew and Elizabeth take the pills to stay awake, when they are found Matthew shouts, "David, don't let them touch her," and there's a visible T-mark taped to the floor in the overhead shot. (01:31:30)
Visible crew/equipment: You can see a crewmember in the woods, when Jennifer throws the huge log at the guys, during the big chase scene. (00:05:20)
Visible crew/equipment: Near the start, after the chopper crashes in the field, while Jack Riley is talking to Von Schauer and George Wilson we can see the small microphone clipped to Jack's shirt under his tie. (00:05:40)