Factual error: The license plate of the car that takes the protagonist to the sanitarium is GR 36E46. That's not a valid Swiss plate: GR indicates the canton of Graubünden, but other than that it is supposed to have only digits and no letters.
Continuity mistake: Early in the film, Lockhart tells his driver to take him to a hotel, and they start down a winding Alpine mountain road before suddenly slamming into a deer. The Mercedes sedan goes off the road, airborne, into the forest, rolling many times before crashing down hard on its side. But, when the camera cuts back to the mortally-injured deer in the road, we see the Mercedes is wrecked on the road shoulder only about 30 feet away from the animal.
Continuity mistake: At the dinner table, the doctor says "My sole concern is for the welfare of my patients." Pay attention to Lockhart during the two following reverse shots: in both those shots the same two elder patients walk by in the background crossing the screen from left to right carrying their plates. (00:46:00)
Continuity mistake: Back after the little adventure at the burg, Hannah gets up from bed. By the window she turns and asks the doctor "When?" and clings to the doll bringing her hands closer, but in the subsequent shot (when Volmer says "Come here") her grip has loosened again and her hands are at distance. (01:23:00)
Continuity mistake: As the train enters the gallery, a close-up shows the box of Nicorette on top of a left corner of the blister pack. When the camera pans (the voice on the phone mentions Delaware), cardboard and blister are side to side, flat. New close-up when he spits the gum, and the two elements are again one on top of the other before he grabs the blister, putting it then back side to side. (00:04:00)
Continuity mistake: When Lockhart suggests Hannah give him her bike, in the frontal shot she is holding her hands away from the proper handle position, but they are back in the correct position in the side view. (01:05:10)
Continuity mistake: When Lockhart sits down to talk to the manager, the glass of water goes from half full to almost entirely full between shots. (00:20:30)
Revealing mistake: When Lockhart slices his cast open, his missing tooth is just cosmetically blackened. (01:47:00)
Factual error: Speaking with Miss Watkins, the protagonist learns of the backstory of the complex, and how in 1814, the local baron was running all sorts of experiments on "his own peasants." The movie though is set in Switzerland, where the power of nobilty was considerably lower and less traditionally 'feudal' than in most neighbouring countries (and stayed as such even after the Congress of Vienna). In particular this castle supposedly is in the canton of Graubünden (aka Grisons), where within the context of the Three Leagues you'd have been hard pressed finding a 'baron' ruling lands, a radical prohibition of nobility, titles and particles having been enacted, surely with no life and death powers over his serfs.
Suggested correction: Even though Swiss nobilities were prohibited doesn't mean anyone with a nobility wasn't allowed to own land in Switzerland. They were simply not priviledged as a noble anymore. He could have been made Baron in Italy, Austria or France. The Count de Salis-Seewis is still a count to this day, with land and mansions and everything, in Grisons. Of course a Baron could still live in a castle in Switzerland in 1814, even in Grisons. The acts he performed on his serfs were illegal and criminal, but he held it secret.
