When Margaret goes to Father Brennan's apartment, he must unlock a well-bolted door. The top lock (a door chain) is fitted incorrectly allowing the chain to easily slip out the hole.
When Margaret's daughter is born, you can see her umbilical cord. When Margaret saves her daughter, the daughter misses the umbilical cord and you can see a belly bottom.
The fashion used by the supporting characters, as well as the extras in the film, do not belong to the early seventies, but to the middle of that decade.
When Margaret and Luz go to the disco together, the first song heard playing is "Rumore" by Italian singer Raffaella Carra is heard. The song was not released until 1974, though the film is set in 1971.
The song "Daddy Cool" by the group Boney M. is heard in the disco scene. This song was released in 1976 and the film is set in 1971.
During the disco/bar scene, the second song heard playing is "Domani" by Raffaella Carra is heard. The song was not released until 1980, but the film is set in 1971.
The disco bar scene is a disaster. It is implausible that two Catholic novices would ever go to such a place, especially dressed as they were. Furthermore, many of the costumes in the scene were from after 1971 when the film is set. Also, four of the five songs that are heard in the scene came out years after 1971.
WRONG: It's said that ambassador to Great Britain would need a newly born kid, but in The Omen (1976), Robert Thorn is appointed as ambassador to Great Britain after adopting Damien.
RIGHT: It is simply wrong what is told here. Gregory Peck in The Omen (1976) aka Robert Thorn is already a American ambassador (in Rome) and was then appointed as the American ambassador in Great Britain. So this is clearly not a plot hole, just someone who did not watch both films carefully and only want to rant.
RIGHT: It is simply wrong what is told here. Gregory Peck in The Omen (1976) aka Robert Thorn is already a American ambassador (in Rome) and was then appointed as the American ambassador in Great Britain. So this is clearly not a plot hole, just someone who did not watch both films carefully and only want to rant.
WRONG: Father Brennan is shown to not be a part of the cult that wants to birth the Antichrist, but in The Omen (1976), he has 666 birthmark on his thigh, which this movie shows only the children born of the Jackal carry.
RIGHT: Any footman of the devil can have a 666 mark, like the bible is already telling us.