That law was found to be unconstitutional on all levels. Thus it is no longer a valid law. Simple as that. Now, rather than being a law, it is a crime to keep it on the books. Unconstitutional is unconstitutional. The end. No part of our government can hold it as law.
Then by your logic, Kim Davis shouldnt be signing ANY marriage licenses at all. Which makes your earlier argument about her not doing her job invalid.