Wow, really? I didn't even blink at that point in this chapter. I hope and guess this thread is sarcastic, right? It clearly shows the 4 people seated in the room on one of the earlier panels, only Hiruzen has white hair. Even my grandmother would understand that, geez xd
Unless Tobi colored his hair, space/timed himself in the room without anyone caring about that and then told Itachi that, lol.
If people didn't get that it was Hiruzen, then how on earth did they manage to pay attention when Itachi explained Izanami?

No offense intended, but this is just ridicules...