A rough and unsparing film.
Above, this may be the best view of all: You can see exactly how the camera is mounted for the shot. The set-up is indeed designed to camouflage that there is no actual hole in the "bank wall." I didn't know exactly why it was done this way when I originally saw the movie, but I had a hunch. Again: It's not a debacle, it's not a Crime Against Cinema, it's a directorial (or budget) choice. Take it for what it is. Then again, it's also a failure of imagination. They can do wonders with opticals and CGI these days (see the astonishing, virtually invisible Digital Domain work on "Zodiac"). Watch the "Zodiac" footage. Or build a bigger/deeper add-on set. Why settle for less?
Here you see one full take, and some of the vehicles returning to positions afterward.
After the jump: Better glimpses of the flats used to extend the building and provide the "hole" in the exterior wall of the Gotham bank...