A. T stops on lenses are new thing. In the past they all used aperture.
B. The lens in question is modified photography lens.>>3751360
It's impossible to say what was actually used, but it was very close to f0.7 based on the dof that they had. One of the lenses was modified to have wider field of view. That could effect actual aperture. Interestingly, Planar's design was in fact a kind of a speedbooster.