I'm thinking caught by a machine, ran on adrenaline/ shock, then finished off by a predatator.
I cannot think of a predator that COULD leave a straight edge like that.
Do they have their young up on the mountain or down in longer grass?
Maybe moving slow as so injured, picked up by eagle or similar, part eaten taking back to nest but dropped?
I found a hare up our lane, still alive, got her to vets but she died, vet said result of being hit by car. Only half km, but still a fair distance to run when you are dying.