Revealing mistake: When Sean Connery and the others are examining the corpse found in the water, the dead body's eyes blink. (01:01:05)
Revealing mistake: When the dead monk is first pulled out of the blood vat, the others dump water on his face to see who it is, and the body's closed eyes flinch upon contact with the water.
Revealing mistake: When we momentarily see the dead Brother Berengar submerged in the water tub, he breathes out a small bubble of air through the water.
Character mistake: When William finds the footprints on the ground after the body is found in the blood vat, he tells Adso that they were twice as deep as they should've been because the person who made them was weighed down by the weight of a body. Adso points out that the footprints were going away from the vats, to which William rebukes him and says that the man who made the prints was possibly dragging the body. If that was so, the footprints would not have been so deep, as the person moving the body would not have been weighed down nearly as much by dragging one along the ground. William is a learned investigator who shouldn't have made such an obvious mistake.
