When you have a snare line found by a badger or fox it's a complete mare, I don't do big trapping/snaring jobs like I did twenty years ago, but when I did and experienced this problem it used to seriously p me off.
Same sort of thing happened on a dairy farm rabbit job I did, traps in every hole, come back in the morning, every rabbit had big holes in them made by rats! Rabbits completely unsalable. ?