I'm not surprised at it being over Rin. When Obito initially proposed going after, Kakashi refused and got bitched out for it. During the fight, Obito didn't die because he couldn't run fast enough, but because he willingly sacrificed himself to save Kakashi. All Obito asked was that Kakashi do the one thing that got him into them mess in the first place: Protect Rin. He even gave up his Sharingan so Kakashi would be better capable to do so. Comes back and finds he still let her die?! Gon' be some shit.
R.I.P. City of Heroes
You will be missed.