I am so sorry, been there before myself. The lack of ethics is the down fall of modern bowhunting in my opinion, mainly one form of bow. Mine happen similarly, I shot a nice Buck, backed out and gave him time, and got my gear. Went in and picked up the trail, which only ran 100 yards. I found massive blood pool. Something didn't seem right, so I started looking around and sure enough I found just short area away, found the pile. My heart sank, my gut twisted and instantly was really mad. I got ahold of the CPO, he came and we talked and they knew that there was someone doing this (they did end up catching them). My only consultation, was that I did everything right, legal and ethically for me and the animal. Just as you do, now wax your string and get back at it.