So sorry for your loss. It’s awful that you’ve had such bad luck with this batch... I don’t ever eat found dead animals, but I agree with Wyorp Rock, that opening it up might be reavealing. Maybe there’s something visible? I had a green spot on the inside of one of my layer cockerel’s leg once, my husband said it was bruising, but it was a very livid green color. (I gave that leg to the Ravens with the guts such as well, just in case)