I'm inclined to say that since the state change itself involves an energy transfer that nothing would happen -- but I'm not sure either. I am confident though (yes, I know that my confidence proves nothing) that if you did the identical experiment under the identical conditions in a hundred different laboratories you would get identical results. If you did get variations, you would look for (and probably find) variables you hadn’t eliminated, including (as you point out) imprecision in your instruments. You would not conclude that water has variable properties.

Now consider your sample assertion:

“In modern democratic capitalist societies, minimum wage laws as typically drafted and enforced generate more benefit than harm to low-skilled workers.”

What do “modern,” “democratic,” “capitalist,” “typically,” “benefit,” “harm,” and “low-skilled” mean? All of these terms are subject to endless interpretation. I am not saying that we should throw our hands up and give up on public policy altogether, but I am saying when people discuss such matters they are rarely, if ever, on the same page.