I think this is straight forward. In our everyday life laws aren’t derived from something else either. They just are. And OP seemed to have a hierarchical view of them as well. They were just under the assumption that a theorem could be “promoted”.
I guess a real-life analogy would be a judge making a ruling under some laws. That would make a precedent in many countries but not a law. If then a new law were passed it could invalidate that precedent similar to someone disproving a theorem.