The finale was very exciting for the most part. Where I felt disappointed was when the daughter mentioned to Sidle and Brass that she used to work at a nursery, planting things, and neither of the investigators caught on to that clue. I don't know if the daughter deliberately gave it to them, or if she was just trying to be dramatic at that moment. In any case, if Sidle had picked up on that, they would have been able to find the place where Nick was buried.
Of course, if they had done this then there would not have been the sequence with the fire ants. That was just disgusting. It wasn't as agonizing as watching Nick about to give up and kill himself.
This flaw in the story really bugs me becuase Sidle and Brass are supposed to be very intelligent officers. How could they have missed that clue?