If so, if both values are God’s will,
then it makes no sense to speak of being in a conflict, or of ultimately deciding between them.
One simply has to hit upon God’s will.
It has nothing to do with making a decision,
because “decision” implies something subject to my own judgment.

That is pure prophecy. How do you know that?
Contrary to your implicit assumption, deciding is not drawing lots. The purpose of making a decision is to arrive at the correct answer. When I have two arguments, each pointing in a different direction regarding God’s will, I must decide what His true will is. If I could ask Him, perhaps I would do so. But, unfortunately, I have not yet reached the level of prophecy, and so all I can do is use the tools of a sage, who is preferable to a prophet.

What bothers me is this: if we have reached the conclusion that both values are God’s will, what is driving the Rabbi so strongly, and why is it necessary to emphasize that morality and Jewish law are two different and independent values? Both lead to God’s will; what matters is God’s will. What difference does it make whether you call it Jewish law or morality?
It seems that it is very important to the Rabbi to separate between the values.

The importance is a matter of taste. First of all, one must agree that the distinction is in fact correct. In my view it is very important to distinguish between these categories, because there are people who identify these categories with one another, and then they make wrong decisions and do not understand the map correctly. For them, deciding by means of the tools of Jewish law also determines morality—but that is not so. The fact that theoretically both are expressions of God’s will has no practical significance. Physics and chemistry are both the work of the Holy One, blessed be He, and still they are two different sciences. So too matter and spirit; and still there are conflicts between them.