That law sounds just plain goofy to me..................
It’s so flat with many, many farm fields that a hunter on the ground firing a rifle can have the round travel a gret distance (toward a farm house etc)...Hunting with a shotgun slug limits the distance and hunting from above ground means you are aiming toward the ground in case you miss, which EVERY hunter has done before at one time or other...
Where are you located, Red Badger???
Not really. The higher the shooter is in the tree, the more likely the shooting trajectory is downward so that a bullet that misses is more likely to plow into the ground rather than carry for a mile or so.