When the kids are on the boat hunting the snake heads, Amber fires at least eight shots from a six shot, snub-nose revolver. Her friend then grabs the gun and fires two more shots from it without reloading.
If "the snakeheads have eaten everything," then how can "the fishing be good?"
(at around 1h 16 mins) When the girls are in the house shooting the fish. The one using the shotgun ejected 2 "spent" shells onto the floor. It was brief but it appeared they had smoke swirling off them but they were still closed and not open as a shot shell would be.
The sheriff's department's cars say "POLICE" on them; if they were a sheriff's department's cars they should say "SHERIFF" on them instead.
When the kids are hunting snakeheads in their boat, the wake from the camera boat is occasionally visible.
The Maryland town has a snow capped mountain range around the lake. The only mountain range in the state is the Alleghany Mountains which is in the northwestern part and are not snow capped.
How did Luke (who fell overboard) reach the island before girls who came by speed boat?
(at around 1h 26 mins) Near the end, a person picks up a collapsed power line to shock one of the mutated fish. If someone put their hands on a collapsed power line, they would be electrocuted.