Continuity mistake: The dressing that is on the evil Dr Leticia Baines's forehead keeps changing. When she is first placed on Grogan's raft, the dressing is soaked with blood. In the next few scenes it just has a small patch of blood in the centre. After she swims to rescue the boy from his canoe, she gets on the raft and the dressing is dry. In the next two close-up shots the dressing is wet (with water) and then it is dry again.
Suggested correction: While the description of the events and the mistake is accurate, it wasn't Dr. Baines that swims out to save the boy. It was Dr. Hoak. You're thinking of the 1995 remake of the film.
Continuity mistake: In the scene where the kids at the Lost River Lake Resort are being attacked by piranha fish, Brogan's daughter Susie is hiding under a blue boat. She tries to lift the boat so she can use it to rescue her friends. It's too heavy for her, so she uses an inflatable boat instead. As she launches the inflatable off the jetty, you can see the blue boat in the water beside the jetty. Moments later, Brogan arrives and picks up the boat from where it was when she was hiding under it.
Factual error: When they drain the pool at the abandoned army station, Paul tastes the water and claims the water is salty. Piranha are freshwater fish and would not survive in salt water. (00:19:30)
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.
Continuity mistake: As Paul races the jeep down the highway behind the RV, he suddenly cuts out and into the oncoming path of a car, where he swerves to avoid a collision. But his jeep suddenly speeds up like a cartoon car, while the other vehicle driver goes opposite. Obviously an editing mistake.
Continuity mistake: The piranha attack the raft, feeding on Doc's dead hand. So Paul cuts him loose into the water, and he floats away, though some of the piranha are still savagely attacking the raft until it reaches shore.
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.
