I thought Ishgard was always kinda tight regarding people entering, but I'm sure the echo has something to do with Aether-y energy and such. We don't know the details exactly, yet. However, we do know that the guy in the opening cutscene never moved from his seat. I'm more inclined to believe that he really did see the past, it's the only thing that makes sense.

One thing SE does do well is keeping all the story facts straight, so I'm sure(I hope...) they wouldn't leave glaring holes in their story like that.