I actually wasn't present during the shoot, although I saw her setting up. It seemed like a semi-pro digital still camera on a tripod. Perhaps it was on wheels? I think it was a fisheye lens? It seemed very low tech. I think all the fanciness is with the post-processing to stitch the photos together and correct the perspective.
You can see the tripod legs if you look down on any shot by clicking the "Down" arrow on the white wheel in the upper left of the interior shots. For our shoot, you can also get a pretty good reflected view in the doorway if you "stand" halfway outside then look left.