Well, Mathematics is symbiotic with Natural Law. -So one could stretch it and say it is a natural law. It is unbreakable, remains in constant and verifies itself from every physical perspective. In other words it "proves itself". -Everything else proves it too.
That's a lot like Natural Law.
Perhaps your point could be valid. ...But I'm certain you can't measure the Sun's natural 15 degree per hour transit from the Southern Hemisphere using the flat Earth map.
You can sure do it on a "ball model" AND in the real world.