My friend proposes that 15:29 implicitly hold that only MAN (and not God) experiences a change of mind'?  He elaborates:

"Saul is protesting against making God like a man. "God is not man."  And he is protesting for the glory of God. "The Glory of Israel will not . . . repent." Therefore, the error of teaching God 'is not infallibly certain of the future', 'can be mistaken' and experiences 'surprise-ability' is to make God in the image of man."

DH is saying that because God is not a man, He will NEVER change His mind i.e. the aspect of mind-changing is something attributed only to Man, not to God.  Well, putting aside the fact that the Biblical writers saw it fit to ascribe over 30 instances of repentance to God (and how this affects the 'holistic-ness' of classical theology on divine omniscience), I'd invite us to examine the following verse:

Hosea 11:8-9, "How can I give you up, Ephraim/Israel?...My heart is CHANGED WITHIN Me; all my compassions is aroused...I will NOT carry out my fierce anger, nor will I turn and devastate Ephraim...FOR I AM GOD, AND NOT MAN..."

Here we have a case of God affirming His own repentance and 'mutability', and linking this with the fact that He is divine (i.e. not a man).  This severely undercuts the classical interpretation of 'Man equals Change, God equals No Change'.  Because if DH can say that God will not change His mind because He is not a Man, I can also insist that God does change His mind precisely because He is not Man!

But this is to harp on a mistaken issue, the distinction of what is an attribute of God versus that which is of Man.  On the contrary, what 1Sam and Hosea informs us is not so much what God can and cannot do in comparison with Man, but the kind of person God is as compared to the persons we are.  It is the CHARACTER of God/Man which is highlighted and contrasted here, and not the (im)possiblity of either repenting.

Scripture makes it clear that BOTH God and Man experiences change of mind and heart. Both divine and human can repent of decisions and learn new things.  What distinguishes God from Man is His heart of integrity and compassion:

1Sam 15 shows the unwavering steadfastness of God in His final decisions - Hosea 11 depicts the mercy of God even in the midst of wrath.

God is one who will not go against a direct and unconditional declaration for a specific situation.  When He says, "I will not change my mind on THIS matter anymore", He really means it!  This is the case in 1Sam 15 where Saul's dethronement is no longer a matter of negotiation or intercessions by anyone, not even Samuel (who 'was troubled, and cried out to the Lord all that night' after God mentioned His repentance in 15:11).

For God is not a man that He will change His mind about what He's firmly avowed.

Nevertheless, it is also the glory of God that any intended judgment and wrath upon His children can be withdrawn due to His incredible compassion which NO MAN comes close to possessing.  This is the case in Hosea 11 where God appeals to Israel to repent of their sin and so move Him to reconsider His judgment (a VERY COMMON theme throughout the Old Testament).

For God is not a man - 'His anger lasts for a moment, but His mercies last for a lifetime', *smile*.

How marvelous is the Person of God!  Compare this to us homo-sapiens who frequently issue out half-baked promises (and having no qualms about changing our minds about them later on) and who tend to be uncontrollably driven by our self-righteous anger towards people...hmm...

Let's move quickly to the final part...