Judging from your wording and from the exif info overlayed on the sample image, I think you might not have bothered defining the lens to the camera as a non-CPU lens.
Had you done that, aperture and focal length info would have been displayed correctly (and BTW matrix metering would have worked OK without reverting to centerweighted instead, which is what happens when you mount an undefined non-CPU lens).
At least this is how one is supposed to work with Nikon's own AI and AI-S lenses and I believe the Zeiss ZF line are supposedly AI-S spec.
EDIT: I now see you have mentioned the non-CPU definition functionality in your article, I wonder why I missed this paragraph when I first read it. Was it there from the start?
Nevertheless, maybe you should also point out that matrix metering does not work without defining the lens as a non-CPU lens.