Another false premise here is that atheism precludes belief in natural law.
I like to think that the Decalogue is a fair summary of the Natural Law from a Judeo-Christian perspective, with "Do unto others ..." thrown in for good measure. Honestly I was not aware that modern atheistic thought puts much emphasis on a natural law. Can you give a thumbnail sketch of that natural law on which atheists of good will would agree, and a brief explanation of the means by which an atheist may derive a conception of natural law? This is not a rhetorical question, for it bears upon the eastblishment of a consensus of "Objective Truth" between the theist and the atheist.