Right before Frankie receives her first wounds as she lies in the bathtub, a bird flies in the room. When the bird flies off a single feather drops into the tub. As Frankie picks up the feather with her right hand, the bloodless wounds are already visible on her inner and outer wrist.
The subway interior shots correctly show a Pittsburgh subway car, but some exterior long shots show a car clearly marked with the logo of the New York Metropolitan Transit Authority. The exteriors were reused from Money Train (1995) (see trivia).
Shortly after receiving the crown of thorns, Frankie is sitting atop a building with no marks whatsoever on her forehead.
After Frankie opens the package from her mother which contains the rosary, she is seen walking over to the table. She is holding a cup in one hand and picks up the rosary in the other. The next shot has the items in her hands reversed.
The same 1977-81 Pontiac Firebird is seen three times. It
shows up two times in the same scene. Frankie is almost hit by the car in the baby scene. She climbs over the hood in the crown of thorns scene and a moment later it drives past as she runs down the street.
The Cardinal is shown wearing a goatee - this is not allowed for Curial members, especially those living in the Vatican.
The priest stated to Frankie that she was the same age as St. Francis when he received the stigmata, 23. In fact, St. Francis was 42 years old when he received the stimata.
The plot centers on the supposed ban of "Gospel of Thomas". In fact, this gospel (along with many other gnostic or non-canonical texts) was never officially suppressed by Catholic Church and its translations can be freely bought in bookstores.
A desperate conspiracy by the Catholic Church to cover up the existence of the newly-rediscovered Gospel of Thomas, which would apparently destroy the entire institution of religion if discovered. However, it was actually discovered in 1945, and published (and translated) shortly after with no opposition whatsoever.
You can see the glass shower door shatter before Frankie throws Father Kiernan into it.
In the bathtub scene, we see numerous shots of Frankie suggesting she is completely naked in the tub (without seeing actual nudity). Right after she places the fallen feather on the side of the tub, the unseen "force" pulls her backwards into the water. As she is falling back, we can clearly see she is wearing a flesh colored bra or bikini top.
After being bodily thrown around an apartment, smashing headfirst through a glass shower door, and having heavy furniture pulled down on top of him, Father Andrew Kiernan shows no bruising, marks, or signs of physical pain (pulled muscles, sprained joints, etc.,) at all.
At about the 15-minute mark, Frankie gets out of Donna's Ford Mustang. The sound of the car door being slammed shut can be heard well before Frankie actually shuts it.
Early on when Kiernan first meets Frankie in a club, she run out back into an alley between multiple buildings and starts having a major attack, with wind, pigeons, and sound effects. Clearly visible are boom mikes and cabling, particularly when the camera zooms out.
Rope visible tied to Frankie's bed
When Frankie Paige receives a package from her mother containing, among other stuff, Father Almeida's rosary, the Post Office stamp on it reads "BRAZIL", when the correct spelling in Portuguese-speaking countries is "BRASIL".
In the scenes in Brazil, people are speaking Spanish and Portuguese with Portuguese accents, not Brazilian accent. It would be like an American countryside movie with English actors playing the roles with cockney accent.
Father Andrew Kiernan states that monks invented alcohol. Even if one grants Kiernan the benefit of the doubt and assumes that he is referring exclusively to alcoholic beverages, he is still wrong. The ancient Egyptians were drinking beer back in 3000 B.C.E., if not before.
Father Andrew Kiernan states that the earth is 6 billion years old. In fact, it is about 4.6 billion years old.