That in the Koran it is written that we believe in the Father, Son and Mary and they got that wrong as we don't...
There may be other misunderstandings in there as well but it's more then just about misunderstandings as ISA could not possible be the Jesus of the Hebrew and Greek Scriptures and why do I say that?
Because the Messiah which the Koran agree's with that He IS the Messiah which does separate Him from the other just a prophet thing and where the prophecies of the Messiah to come is found IS in the Hebrew Scriptures.
Even God's duel nature of being IS found in both Scriptures as well.
Even many Messianic Jews do see that.
It's not just a Christian thing.
He is Holy, Holy, Holy!
Our God Almighty!
It's not a mistake.