I worry about just this thing happening every time I mow the grass here. There's a lot of trees so I usually walk around first to pick up after my dogs & all the sticks. I use a small walk-behind battery-run Greenworks because this place is an obstacle course- no riding mowers here- & I keep a watch for any of my tiny neighbors- I worry about the little snakes & toads & sometimes move them to the safe areas of groundcover. So far I've not hit anything that I know of...I feel for you & hope he's okay. The trouble with humans is the world we make is very rough on wild things.