there is no such things as coincidences
pretty sure in the time frame of the last chapter prabaly a year passed as we saw in the begining short hair later on long hair.
this is the time where madara controls the hidden mist (bloddy mist) so no im not surprised if he has anything to do with it, pretty sure the real rin died, and kakashi was supposed to die as well.
a lot of ppl think that when tobi is first introduced that the zetsu not obito...lol ima have to disagree on that pretty sure it was just a cover up , all uchiha should have been dead only itachi and sasuke remained he was just keeping a low profile till thier plan was complete