Perhaps, but all you need to do is create doubt. If I had sat on the Simpson jury I wouldn't have convicted him. The cops had their hearts in the right place when they tampered with the evidence, but it open that big door known as "shadow of a doubt". If the cops and prosecutors follow the laws of the land and the proper procedures, you don't run into problems like this. If Peterson get's off they'll have no one but themselevs to blame.