The injury on the bridge of Daggett's nose keeps changing size and shape.
The red Ford pick-up truck has a winch on the front bumper in some scenes, in others it does not.
When Simon takes Hawthorne's soul in the church, the flag draped over the casket changes positions from shot to shot.
When Gabriel opens the saw of the corpse of Colonel Hawthorne, he leaves it open. The next shot has the Colonel with his mouth shut as we found him.
There's no wrench in the front of the truck in one scene, but it appears in the next.
When Thomas is looking up Uziel there is a drawing of Gabriel on the next page. The drawing is in fact Archangel Michael by Martin Schongauer.
The Book of Revelation contains a warning about adding or subtracting from it. Thomas Daggett, being a former priest, would know this. However, they are talking about adding to it through Satanic possession and false prophecy. Revelation hints that those who do add to it will suffer the same fate as those who receive the Mark of the Beast. Daggett, knowing this, would likely not have even read it.
Mary's Grandma says that Mary will have a sing called the enemy ghostway. Navajo Ha'atali, or, singers, may perform an Enemy Way sing, but there is no enemy ghostway.
When Thomas is in Hawthorne's apartment, he finds a movie reel marked as police evidence. If it is evidence, it should be safeguarded in a police precinct, instead of inside the deceased's home. But Hawthorne is evil and intelligent. He could have found a way to purloin the incriminating evidence.
When Gabriel steps through the doorway to exit the mobile home, and the door flings open by supernatural power, we can see the string at the top of the door that pulls it open.
When Gabriel opens the freezer door at the morgue, a crew member's movement is reflected in the shiny part of the handle.
As Thomas looks through Hawthorne's press clippings, a zoom-in shows that in the text of one of the articles, the word "preliminary" is spelled "perliminary". Also, there are two non-existent words: "Presidentedly" and "heruman".