The William Butler Yeats poem is misquoted on the door in Dr. Hobby's office. Dr. Know reads it "Come away, O human child! To the waters and the wild..." This is the correct line, and also what Gigolo Joe says as he reads it. However, the lines on the door read "To the waters of the wild".
When the robots open the frozen door to the Amphib Craft, David's trousers are already wet on the left leg from the knee down. But when he gets out, they are dry and twice he slips on the ice and both times he lands on his left knee.
When Dr. Hobby removes the CPU from mecha Sheila's forehead, the module is about as big as a walnut. But when he holds the module up to show to his colleagues, it is a cube about the size of a billiard ball.
Monica takes David to the forest to abandon him. While she is telling him her plan, the sun is shining brightly on David's head and hair when the camera angle is showing Monica's face. However, whenever David's face is shown, his head is in shadow.
Much of the film's early action takes place in Haddonfield, New Jersey. New York City is subsequently shown to be under water. Haddonfield's elevation (81 feet) is lower than that of New York City (87 feet), and it is near both the Atlantic coast and a river leading to the ocean, so Haddonfield should be under water too.
When the alien spacecraft is approaching the former World Trade Center the towers are in the incorrect places in relation to where they are going. After passing them the craft approaches the Chrysler tower implying that they went north. However, back when they are approaching the towers the North Tower (the one with the antenna on it) is on the right and casting a shadow on the south, meaning its closer to the camera. The only way for this view to be possible is if they (the aliens) were heading east as the North Tower is further north than the south. This would mean that they are heading somewhere into Brooklyn not Midtown Manhattan.
At the end, it is stated that a person can only be resurrected if the Mechas have access to a person's DNA. Teddy gives David the lock of Monica's hair David had cut. However, cut hair has no DNA, and the chances that the lock would have some non-degraded skin cells of Monica's and only Monica's is extremely remote.
When the robots are in the cage at the Flesh Fair, the little girl tells her dad about the boy in the cage. On a screen above his head, we see a replay of the "spider" type robot with the human-like head destroyed. He is then taken moments later when David grabs Joe's arm. He is then destroyed in the same manner as the so-called replay.