Let me make myself clear. I did NOT posit that morality is created by law ITT. Morality comes from many places. However, the origin of morality is a non-issue in this question. We dont need to debate something so subjective, when the problem begins with two opposing moralities. Regardless of where it comes from, here we stand with two different ideas of right and wrong. Law can help settle disputes when such differences arise, but alas, we've taken that away in the problem.

Im giving the farmer the name Fred, and the taker the name Tom for simplicity.

In its simplest terms, Tom took something from Fred. Now, you cannot say Tom is wrong without invoking law. Sure, Fred thinks Tom is wrong. Sure, many people agree with Fred. But many people also believe women should still be stoned to death for minor infractions. Tom never agreed to Fred's belief. Tom may not even know what Fred's beliefs are, nor how they may differ from his own. Without law, Fred's belief is non-binding on Tom. Tom abides by his own beliefs, and his own beliefs say hes in the right.

I'll make my previous argument clearer too. You've said before that the social contract theory is bogus because no one ever really "agreed". Apply that standard here. Tom is absolutely free to take whatever he wants from Fred, even kill him if he so desires, because he's never agreed to any rules or standards saying otherwise. For the same reason you say Taxation is theft, I say Tom has done nothing wrong.

How can you say otherwise without appealing to some higher standard that is binding on all persons?