God's "subordination" to morality – semantics and wordplay?

A discussion recently developed on Facebook between your student Rabbi Dr. Moshe Roth regarding a book he published called Truth and Obligation, and Rabbi Chaim Navon, who published the book.
I haven't read the book. And I don't know exactly what it's about. From Rabbi Navon's post it appears that one of the issues discussed in the book is the relationship between religion and morality and God's submission or non-submission to moral laws: Rabbi Chaim presented a position. I was quite surprised to hear from a personality who is considered as conservative as he is that God is supposedly subject to moral laws just as He is subject to the laws of physics, logic, and mathematics, and that it is impossible for God, according to Jewish tradition, to determine that 1 plus 1 equals 4.
Rabbi Roth presented a position from the other side of the fence, according to which all sources show the opposite.
 
What is the relationship between Halacha and morality? It is well known that both are the will of God, which in the event of a conflict is decisive based on considerations for one thing or another.
 
But what caught my eye in this matter is the definition of God as supposedly subject to something – don't you think this is a play on words? Although in tradition, statements are often made that God can never break the covenant with the people of Israel because He is a true God or cancel the laws of the Torah because there can be no concept of a change of will with God, but all of these, in my humble opinion, are concepts that are borrowed and do not claim that there is anything that logically or fundamentally prohibits God from acting in such a way that He has announced in the Torah that His conduct is thus and so, and therefore there is no reason to assume the possibility that He will break them.
 
 
Do you think this is a play on words or is there something to it?