In Prof. Crey's chemistry lecture on alcoholic fermentation, the blackboard reads 'Rohrzucker' (cane sugar), at 34'05'' into the film the molecular formula 'H6 P5 O11' is visible, utter nonsense (if not on purpose); the correct formula for cane sugar is 'C12 H22 O11', and phosphor (P5) is completely wrong.
When Knebel draws a nude on the blackboard you see thin lines that help him trace the drawing.