During Father Brennan's flight to the church, lightning strikes near him two times; once it strikes the fence just after he scales it and the second time it strikes and severs the lightning rod, impaling him. At neither time is the lightning strike accompanied by the sound of thunder; a lightning strike so close to the priest would be accompanied with almost simultaneous thunder.
On the wall in Damiens' room is a child's drawing of the Nina, the Pinta, and the Santa Maria, on the sails of each the red cross pattée, a form of the 'crux immissa quadrata.' It is highly unlikely that the child would not have recognized or sensed the religious import of these crosses given his reaction to the icons at the church. He would have rejected having any interest in duplicating them.
When the photographer shows Ambassador Thorn the newspaper account of the priest's death, the headline has a grammatical error. It reads: "Freak accident during yesterdays unseasonal storm". "Yesterdays" should be "yesterday's".
At the end when Robert Thorn takes Damien in the car to take him to the church, Robert clearly puts a car key into the ignition to start the car. The 2006 Lexus GS which Robert drives throughout the movie, however, does not have a conventional key with ignition, but instead has a key-fob with push button start.
During the final chase scene, Robert is seen holding Damien down with his left hand while Damien kicks and screams. However, when he is shown driving, he is using both of his hands to steer the car. With each cut back to Damien, he is being held down again.
When the photographer took the picture of Father Brennan as he was leaving the building where Damien's father worked at, the guard escorting him had no weapon visible. However, when the photographer was developing the pictures in his studio, the picture of Father Brennan and the guard could be seen and the guard was then shown holding a type of automatic weapon.
During the scene in which Katherine brings Damien to visit Robert at work (near the beginning of the movie), Damien is clearly seen being carried in her arms. However, when Robert finally meets with Katherine to inform her of his promotion, Damien is no where in sight.
When the armed police arrive in the church at the end of the film a police officer raises a hand gun and fires it, only one shot is heard but then another officer lowers a rifle which is smoking as if it had been fired.
When Ambassador Thorn arrives at the Embassy after the nanny suicide, one of the reporters is played by Harvey Stephens, the original Damien from 1976. When Thorn is heading towards the door he is followed by Harvey Stephens at his right side. In the following shot, when we see them walking towards the camera, Stephens has moved to the left side of the Ambassador.
Father Brennan asks Robert Thorn to meet him at Bishop's Park, by the bridge. Bishop's Park is in Fulham/Putney, which is in SW6. However, in the scene where they meet, the camera pans over a street sign for Orange Yard W1, which is in Central London close to Soho.
When Robert goes to the opera to see Richard Strauss's "Salome," the final bars of the opera's music are heard, and the next scene is Robert in the lobby, about to be approached by Father Brennan. Soon after, the house lights began flashing to indicate that intermission is over. "Salome" is a one act opera, no intermission is given.
The skeleton of the baby in the grave appears to have a fully formed skull. If the child died as a baby or even a year later, the sutures would not have closed up yet, leaving the skull basically in pieces.
When Father Brennan visits Robert at the US embassy in London, the US flags in the background can be seen resting on the floor. It is against US regulation to have the flag ever touch something beneath it, especially the floor and unlikely that such an offense would go unnoticed by the government officials working there.
When the spike falls from the church tower to kill the priest it goes through a stained glass window. In slow motion, you can see the glass breaking completely and then the spike appearing out of thin air, when it should have been visible from the very first break in the glass.
When the limousine is collided by the gasoline truck, the impact of the explosion would have caused damage to the car. The car is in perfect condition throughout the entire explosion - it even keeps it's sheen.
At the beginning of the film when Robert Thorne is being driven through Rome, the date is June 6th and the time is specified as being sometime after 6.00AM (the time the babies are born, which he misses). The sun rises in Rome at 5.30am at that time of year, which would mean it would be light outside, but Robert is being driven in the dark. The original 1976 film made exactly the same mistake.
A bubble of air in an IV line would not be able to go through
the pump. The pumps notice when there are air bubbles and beep, saying "air". Even if this pump did not have this feature, which is highly doubtful, the air pumped into Kate's vein is not a lethal dose.