Board Thread:Naruto Discussions/@comment-3232093-20140617193601/@comment-4271790-20140821170855

And to answer the thread's overall question, (and to beat on a dead horse) yes, Hagoromo probably did have the Mangekyo Sharingan/EMS, and his own special chakra allowed him to awaken the Rinnegan eventually. It's just that his "special chakra" went to Asura, and his presumed Sharingan went to Indra.