There is no way that is Izanagi! When Izanagi occurs the corpse disappear, here you could see Madara's corpse lying there. Also, madara have the sword scar on his chest presently.

Hashi also stated "I'm sure I killed my friend" (there could be something to that statement).
So lets think out of the box now:
*Is it possible the Hashi's wood clone attached it self to Madara, after all he loved his friend so much. It also make sense with the invention of zetsu, a primitive close of Hashi that has a mind of its own.
*Or maybe Hashi tried to do CPR, or some emergency medical jutsuu but thought he failed, and madara woke up later?
*It is kinda tough to think an Uchiha saved mandara knowing we have not seen a medical uchiha in the 635 episodes of Naruto.
*But we should also put into account that Hashi and Madara trained together when they were young and Madara could have learned some life saving Justuu from Hashi. {Remember Hashi could read part of the Uchiha scroll without a sharingan}.
If i were Sasuke I really do not see why this flashback could change my mind because it just proved that Uchihas are jerks. So do not be surprise if there is more flashbacks, maybe from another Kage.:dunno:
But i am so enjoying Naruto at the moment. More stories please.......:bouncy: