Other mistake: When Steve, wearing his improvised shark cage, heads underwater to turn off a relay to prevent the others from being electrocuted by a falling wire, he is shown breathing through a snorkel taped to several metres of hose, open at the surface end. In reality, human lungs can't expand enough to pull fresh air through more than a couple of feet of hose. That's why diving hookahs use an air pump to feed air from the surface to the regulator mouthpiece.
Factual error: When the underground garage of the market is flooded, the car that Kyle and Heather are in does not flood. A car is not water tight like a submarine. Even though the water does not cover the top of the car, water would flood the entire car within minutes.
