Here comes an angry fan to scream He's Batman!!! Well, that is fairly easily rebuffed by the fact that Christopher Nolan's Batman isn't a superhero in the comic book tradition he is more hero and more human than the comic book versions, and as such he must be judged by an appropriate set of rules. That makes his incredible reappearing act quite difficult to take considering he was marooned hundreds of miles away from Gotham, with no access to money, a mobile phone or a sharp, well-tailored suit.
And yet, without so much as a hint at how it was done, there he is, standing smugly within the Gotham boundaries without so much as a dishevelled jacket to explain his journey. I mean obviously, the first thing he would do would be to head home and get his best clothes on.
Regardless of whatever suggestions are thrown up for this, the long and short of it is that Nolan's script failed to address the issue, and it's just not right leaving such a detail to assumption or presumption, and it is an unfortunate and all too visible contradiction to Nolan's realistic approach. Of course the director shouldn't be forced to spell every last thing out for timing reasons that's just not reasonable but there are economic ways of implying things, instead of simply leaving it all open to wild speculation. That's not story-telling at all.
And again, if you have to resort to saying Because he's Batman, you may have missed the point of Nolan's films.