Having obscure routes which even the developers are not aware of is http://img.photobucket.com/albums/v716/zediker/Halgar_picture000.jpg.
The problem there is that they have found areas they werrn't supposed to ever get to, so there are no skins.
In Brink, every single object in the game is designed to work with SMART the way you would expect, so the players are free to find their own way around the map.
And because of the way the game only loads part of the map at a time for optimization, they wouldn't necessarily have to remove walls that you cant see to save memory, so there's less chance of issues like that screenshot.