Revealing mistake: When Lanser goes below deck frantically trying to find people and tell them to leave the ship, when he opens the door at end of the corridor, it's a bit too obvious that the hallway behind that door is nothing more then just a painting.
Revealing mistake: When Lanser drops the cup, you can quite see that he is drinking from an empty cup, since the steward never poured him any and yet he manages to get some of it on his suit.
Other mistake: Lt. Mueller's German accent drifts in and out.
Answer: #4: That he did personally murder at least 14 (Jews). The last word I couldn't quite hear because of the screams, but I hear an "-oz" sound at the end, so it's an educated guess. #5: That he did sign and put into effect specific orders calling for the gassing and cremating of one million human beings.
Bishop73