I really am starting to think that from the point of view of the Doctor, Episode 5 has already happened. I believe he was absent from their lives for a long stretch of time when he showed up for episode 5, and after the events of the episode, he couldn't deal with the heartbreak so he went back into their time stream during the gap of years that he wasn't around. So as the viewer, we are seeing events unfold from the Ponds point of view, and to them it looks like The Doctor is just coming around to take them on an adventure. From The Doctors point of view, it's Episodes 5, 4, 3, 2, 1 and from the Ponds point of view, its 1, 2, 3, 4, 5.
There is evidence of this in "A Town Called Mercy" where they are walking into town and the Doctor says that something isn't right. Rory talks about the street lamps and The Doctor says that its 10 years too early for that, and Rory responds that it's only a few years out. The Doctor then says to Rory "
That's what you said when you left your phone charger and King Henry VIII's suite". Not a big deal, could have happened off screen however:
The preview for "The Power of Three" (episode 4)

You can see the phone charger. So this could mean either he was describing an event that he witnessed already that was in the Ponds Future and they don't know about it yet, or in episode 4 there are flashbacks to things that happened before "A Town Called Mercy". But right now it seems to me that he described something that hasn't happened to them yet.