A redated post.
Explanations, causal or non-causal, involve ontological commitments. That which plays an explanatory role is supposed to exist. Therefore, if we explain the existence of the presents under the Christmas tree in terms of Santa Claus I take it that means that Santa Claus exists in more than just a non-realist “Yes, Virginia,” sense. What this means is that even if reasons-explanations do not exclude physical explanations, even if reasons-explanations are somehow not causal explanations, the naturalist is not out of the woods. The naturalist maintains that the universe, at its base, is governed by blind matter rather than reasons. So if reasons-explanations are true, we still need to know why they are true and why reasons exist in a world that is fundamentally non-rational.