That doesn't sound too good, I'd discard these but don't give up. We pluck ours before hanging. Our unhung chickens were quite chewy so we started hanging for a week and oh what a difference lovely flavoursome tender meat. It's been cold here so the barn is safe to hang in, are you somewhere warmer, perhaps your bird had a wound and bacteria from the faeces got in, who knows, have another go
Good luck, Helen