The Note (spoiler) and couple a the end (spoiler)
Did I miss something or did they not show the note that "The Knife Salesman" write? They show him write it and he pulls it out at the end, but they never show it. I understand McGuffin's, but this really isn't one as it really had nothing to do with moving the plot forward. I assume he wrote a note to his daughter as he assumed there was a good chance that he would die. So in the end maybe it really wasn't important.
Also, the couple at the end were really dumb. Just take the money and tell the guy you wouldn't say anything and then turn it over to the police.