Board Thread:Naruto Discussions/@comment-24120130-20140607191120/@comment-24531362-20140623105932

So, I hate to say it, but Elveonora is probably right here. Haguromo has been confirmed as knowing next to nothing about Kaguya by Black Zetsu. He did not know that she was the Shinju, that she had a Rinnegan, or that Black Zetsu ever even existed. He did know that his child was born in possession of a Sharingan, and reasoned that the trait had to originate from himself,and therefore could be traced backwards to the originator of all chakra abilities, Kaguya. Because Haguromo himself believed his Rinnegan to be unique, he simply assumed that Kaguya must have had a Sharingan, and that her abilities were, therefore, Sharingan abilities. He never even considered that Kaguya had a Rinnegan, nor did he envision a Rinnegan superior to his own, possessed of abilities his lacked. Therefore, Haguromo's insight as to Kaguya's dojutsu becomes both correct and incorrect, thanks to a little help from Black Zetsu.