Revealing mistake: After the two teens enter the waste water plant and begin swimming, the boy gets attacked and killed by the unseen piranha. Yet the girl does not see nor react to the huge pool of blood around her as she swims off.
Revealing mistake: You can see the stomach of the dead child under the blanket rise and fall.
Revealing mistake: You can see doc's stomach go up and down once in the foreground, though he's supposed to be dead.
Revealing mistake: At the beginning when the teens break into the waste water plant and start swimming, the boy gets attacked then killed by the unseen piranha, and a large blood pool spills out into the water. The girl is but 3 feet away, but somehow doesn't' see the blood as she calls out his name and scolds him for not responding.
