I bet it has happened. You'd be surprised what you see if you do not own a car, live where distances start at three miles and there is no public transportation. (And you live in a place of real weather.) I didn't own a car until my early 30s. I've ridden in storms more than a few times. I build and mount my front wheels inside spokes pulling because I fear that branch wedging between wheel and fork. Fallen branches have taken me down but so far, not by opening rear facing front QRs or jamming in my fork.