Board Thread:Naruto Discussions/@comment-3297904-20150325023132/@comment-25319479-20150325025434

If he told Hiruzen the truth, i would expect the news to of somehow be leaked to the Uchiha clan or if he returned back to the clan with a missing eye, they would assume Konoha had something to do with it and immediately provoke them into rebelling against the village. His death was necessary.