Deleted scene in trailer
Remember when Karl breaks in the door at the rich lady's estate as the party is going on? He sees the girl and approaches her to attack. Then suddenly he pivots and focuses straight on Dr. Stein. Ever wondered why? It's because in the trailer Stein shouts "Karl!" getting his attention. That was obviously cut from the film, possibly because he didn't want to draw attention to himself. But without that shot it doesn't make sense that he would suddenly turn and look EXACTLY where Dr. Stein is standing and then make his way there. Those of you with the DVD can view the trailer and see what I mean.
"Cum Grano Salis"