Corrected entry: When the survivors battle the dead outside the shack, there are closeups of the humans that show them firing, switching from real time to slow-motion then back. In these shots, the girls' guns change between shots. They go from firing shotguns in real time to holding pistols in slow-mo, then back to shotguns in real time, or vice versa.
Corrected entry: Anyone notice the extremely localized storm on the boat? It doesn't rain anywhere else but on the boat.
Corrected entry: Note that when Greg is killed, he dies with a hand grenade strapped to his shoulder. (The weapons hadn't been passed out yet).