After the gun fight at the cemetery. Jim and Toms boat hits the top of the statue and causes damage to the outboard motor. So when they start of again you can see the motor waggling about. There is a short second only scene inserted, that shows no damage to the motor. Then it goes back to waggling again.
When the armored car stalls, it is near the middle of a dip in the road. Later the water is chest deep next to the car, but when the robbers cross the water it never gets much deeper than waist depth. As the middle of the dip would be the lowest point, the water depth should have been much greater.
When Karen is handcuffed to her staircase and Tom shoots through the cuffs, she places the chain of the cuffs on top of the banister. This is a physical impossibility because of the way she was cuffed there.
Electrocution powerful enough to set wet clothes on fire would cause instantaneous death. Even discounting this, the burns on Kenny's body would be far more widespread, whereas none appear to be present.
Cars submerged in water do not float on the water surface as they did in the movie. If a car is driven (or falls) into water, it will stay on the surface only until the air trapped under the hood and the trunk / passenger department has been displaced with water.
Actually, firearms and ammunition will function wet, even underwater. What could keep a semi-auto from functioning eventually would be washing away of lubrication, if the water itself did not provide enough lubrication. Revolvers, pumps, bolt actions would not be affected immediately. In a matter of days, rust might keep them from functioning.
For ammunition, water would need considerable time to seep in around the primer and bullet. Many primers use a sealant after insertion to prevent this. Deactivation would be a matter of days or weeks.
For ammunition, water would need considerable time to seep in around the primer and bullet. Many primers use a sealant after insertion to prevent this. Deactivation would be a matter of days or weeks.
During gunfights between Jim, Tom and the police, Jim and Tom have one revolver and one semi-automatic handgun between the two of them. Yet, they seem to have an endless supply of bullets, with no apparent access to extra bullets. In fact, Tom retrieves his gun from one of the dead robbers, but not the bullets. Also, we never see either Jim or Tom reloading their guns from their supposed endless supply of bullets.
Wet ammunition, not to mention wet handguns and rifles, are incapable of being fired, unlike the numerous weapons in active, repeat usage here.
While Tom and Karen are in town, the water is going over the Transformers which attached to the telephone pole which as approximately 16' feet off the ground. The cemetery which is located just outside of town, the water hasn't reached the top of the grave mausoleums.