Other mistake: During the scene where Tom Hanks brings Sophie to his colleague's house in England, there is a chess board. The chess board is incorrectly set up as any chess player will tell you that the white king belongs on the fifth square from the left. In the shot, the white king is one the fourth square from the left, ie. he is switched with where the queen should be. Teabing would definitely know how to set the board up properly.
Continuity mistake: When Sophie gets out of the back of the armored truck, she is not carrying anything and, again, as she is running along the side of the armored truck to get into the passenger's side, we see both hands and she isn't carrying anything. A couple of scenes later, as she and Robert walk up the steps to Chateau Villet, she is carrying her gray overcoat and handbag. They can be seen even better when Teabing is kissing her hand in welcome.
Continuity mistake: When Robert is trying to convince Teabring not to call the police, he takes the keystone box out of his jacket pocket and holds it up for Teabing to see. In the shot of the box in Robert's hand with Teabing looking at him, the rose is facing towards Robert. As the camera position switches to focus on Robert holding the box, the rose is now facing towards Teabing.
Continuity mistake: When Robert and Sophie are inside the bank, we see a bird's eye view of the key on the edge of the table with the chain's sides next to each other with no space anywhere along the entire circle. This shot is just before Vernet comes in to introduce himself. He walks toward Sophie who is behind a table with a chair also between her and Vernet. Right after Vernet says that first-time users are sometimes uncertain of protocol, we see a close-up of him taking the key off the table. First, he could not have reached the key from where he was in the previous shot, plus he is at a different angle to the key and table when he takes the key than in the previous shot. Second, when he does take the key, the chain is in a different position and has separated so that there is a space between the two sides at the top of the curve and at the top of the key. (00:42:40)
Continuity mistake: When Sophie is backing away from the American Embassy, she shoots through the small gap between the trucks, Robert's rear view mirror is knocked off and then the car slams into a pole, bending it completely over when she stops. As she drives away there is no dent, no mark, no sign whatsoever that the rear of her car has been touched.
Continuity mistake: When Sophie and Langdon arrive at the park and Sophie shows the drug addict at the park bench her badge, the shot from behind you can see Sophie close her badge wallet, then when the shot changes to a front one of Sophie and Langdon you see her close the badge wallet again.
Plot hole: The Louvre is home to art worth millions. Even with the electronic security measures in place the museum would be guarded around the clock by armed guards thus making the entire idea of the shooting of its curator and his killer escaping impossible.
Factual error: When Teabing is almost arrested by British police at Biggin Hill, all the police are armed. Throughout all the shots, however, the windshields of the police cars are blank. All cars that carry armed police have three yellow dots on the windshield.
Continuity mistake: When Sophie asks Silas on the plane if he murdered her grandfather she takes the tape off his mouth for him to answer, but when it cuts to the window where they all look out, you can see Silas in the background with the tape still covering his mouth.
Factual error: People who've actually been to Rosslyn (the correct spelling, though it is in the village of Roslin) Chapel will be amused to see in the movie that Tom Hanks and Audrey Tautou were somehow able to bypass the many security guards, the gift shop, tea room, museum and admissions desk to get into Rosslyn, and also that they did so via a door that is always locked beyond two stout gates. No one ever enters Rosslyn the way they did.
Factual error: "Madonna of the Rocks" hangs in the Grand Gallery, not the Salle des Etats. The painting directly across from the "Mona Lisa" is Caliari's "The Wedding Feast at Cana." This painting is an enormous 32 feet (9.9 meters) wide. Even if "Virgin of the Rocks" did hang opposite the "Mona Lisa," it's 6.5 feet (1.99 meters) tall, too tall for Sophie to see over. The painting's ornate wooden frame is also too heavy for an average person to lift unassisted.
Audio problem: When Langdon removes the clue from the Cryptex box lid and takes it to a mirror, Teabing says "Backwards, in the style of Leonardo himself" without his mouth moving. Although much of the shot is shown over Teabing's shoulder, his mouth is visible at the beginning of the shot, and his jaw does not move throughout the rest of the sentence. (01:27:45)
Plot hole: Fache says he believes Langdon killed all those people because Aringarosa told him Langdon came to him in confession over the murders. We know Langdon made no such confession, so what made Aringarosa involve Langdon in the murders in the first place? Aringarosa never saw the curator's daily planner, his email, and wasn't there to see the message on the floor, so other than Langdon conveniently being in town for his book signing, why did Aringarosa name Langdon? If he was just telling that to Fache so he would have someone to arrest, Aringarosa could have named anyone.
Revealing mistake: When Langdon comments on the geometric pairing of the two pyramids you can tell the point of the crystal pyramid is slightly to the left of the point of the other pyramid.
Factual error: In Sophie's flashback to the accident that killed her family, they (and the oncoming truck) are driving on their left side of the road. If this happened in France, they should be on the right.
Plot hole: If you don't have Jesus' DNA, only that of Mary Magdalene, how does it prove anything other than that Sophie is related to some lady? It would still not definitively prove Christ was married to her or that he was not divine.
Character mistake: Langdon points out that the Templars were slaughtered on October 13th, 1307, and Sophie comments, "Friday the 13th", implying that this is when the fear of Friday the 13th originated. In reality, fear of Friday the 13th didn't really begin until early in the 20th century.