Goofs

While defending the hospital from hordes of zombies, Peter and Brian throw Molotov cocktails at the entrance. Despite throwing several that result in fireballs and flames, each time one is thrown the hospital entrance is clear of any flames.

During the shark vs. zombie fight the zombie tears a chunk of flesh off the shark. After an initial gout of blood there is no subsequent sign of either the wound or any blood in the water.

During the shark vs. zombie fight, the zombie gets his arm bitten off. However, we see him with the arm after he loses it, and without the arm before it is bitten off.

After Brian has killed the zombie that has killed he has a small drop of blood on the right armpit of his shirt. When he arrives at the hospital, his shirt has been doused with blood. After dispatching the first zombie, his shirt has a lot less blood splatter on it.

When Dr. Menard's wife is alone at the cottage she pushes the dresser up against the door twice.

When Brian fires a rifle at the shark from the boat, he fires the rifle multiple times very quickly. The rifle he is using is a bolt action rifle, which must have a bolt part moved before each fire. He does not touch the bolt. In addition, Brian fires more than five times, and bolt-action rifles usually have but 5 rounds in the magazine.

In the last scene, the radio announcer in New York City states that the governor has declared a state of national emergency. Only the President can declare a national emergency, not a governor of a state.

The flare's fall sounds like an incoming bomb.

The harbour patrol, later referred to by police as National Guard, are dressed as NYC cops in blue shirts and black leather jackets.

It's NYC harbour and the boat is flying a French flag.

When Dr. Menard is driving and discussing the zombie plague with the visitors, the "clean" part of the jeep's windshield (i.e. the path of the windshield wipers) appears to be cut out of the glass (probably to provide a better view of the actors and prevent the camera being reflected on the glass).

While the zombie is fighting with the shark, the parts of not rotten flesh can be seen on him.

When heroes escape from Menard's cottage, one of the crew is reflected in the window of the jeep.

In the final scene, it is revealed that the zombies are causing havoc in New York City. A large horde of them are shown shambling across the Brooklyn Bridge into Manhattan on the walkway designed for pedestrians, but below the civilian cars are shown calmly and orderly driving across the bridge in both directions. This makes no sense:

1. Traffic on a bridge like that can be heavy during rush hour. During a zombie apocalypse, traffic would likely come to a halt due to a few crashes and the falling apart of towing companies/authorities, not to mention everyone frantically trying to leave.

2. Why would regular civilians be going into and from the zombie war zone in an orderly fashion?

Depending on the direction of traffic, it should either be totally chaotic or nonexistent. Obviously the director reserved the top of the bridge for the zombie extras without restricting access to the roadway below.

When the homicide detective is questioning Tisa Farrow's character on the boat he says a member of the "coast guard" was killed. The man who was killed on the boat at the beginning was clearly a member of the New York City Police Department.