I don't understand what's KPKB Icy 
but actually all of them committed errors.
Job was faitful all throughout the story. But his fault was that he
bacame overly-self righteous.
His friends on the other hand said some good and erroneus
viewpoints.
Good viewpoints of his friends particulary Eliphaz:
1Co 3:19 For the wisdom of this world is foolishness with God. For
it is written, "He catches the wise in their own
craftiness";
that's Paul quoting Eliphaz in Job 5:13.
But they also said some wrong things. They equate calamity and
disaster happening to an individual as a sign that that particular
person must be wicked and had done something wrong terrribly.
That's why God is punishing him [Job]. But that is wrong Job was a
righteous man.
In the end also, Job had to repent of his being overly-self
righteous attitude. And he had to interceded for his friends who
said wrong things. here:
Job:
Job 42:5 "I have heard of You by the hearing of the ear, But now my
eye sees You.
6 Therefore I [Job] myself, And repent in dust and
ashes."
7 And so it was, after the LORD had spoken these words to
Job, that the LORD said to Eliphaz the Temanite, "My wrath is
aroused against you and your two friends, for you have not spoken
of Me what is right, as My servant Job has.
8 "Now therefore, take for yourselves seven bulls and seven
rams, go to My servant Job, and offer up for yourselves a burnt
offering; and My servant Job shall pray for you. For I will accept
him, lest I deal with you according to your folly; because you have
not spoken of Me what is right, as My servant Job
has."
