Revealing mistake: When Dr. Heiter takes Katsuro from his car, you see Heiter drag him out of the back seat. He then proceeds to lift Katsuro. If you watch Katsuro's hand, you'll see he "helps" Heiter by pushing himself on the door-frame of the car (you see his hand tense as he pushes himself up).
Revealing mistake: When Doctor Haier is explaining the operation to the captives, he says he'll sever the ligament in the knee. However, around the 1-hour mark when the captives are walking by the pool, you can see the rear woman's leg raise her left foot off the floor when she moves forward, showing she still has control over her knee.
Suggested correction: He explicitly states that the ligament severed prevents the knee from being straightened, not bent.
Revealing mistake: The victims are supposed to be surgically connected mouth-to-anus. The majority of the time, their heads are far too high to be connected this way.
