We're basically arguing semantics at this point although my description of the issue as shadow detail evades your concerns here. It's a matter of perception. He described "shades" that were all too dark to be perceived as grey tones in his mind. Had they been presented individually, any one of them would have been regarded as black. On a display, if there's no differentiation among the darker values, you lack detail at that range. Basically they're clipped.
Okay on cmyk it works a little different. I'm not going to argue the pigments vs colors of light thing because it never provides an accurate description. Think of it this way.... with the technology available, mixing those three inks doesn't yield a completely neutral black in darker values. They use a specially mixed black ink to compensate for the fact that on paper in typical viewing conditions, the mixture of cyan, magenta, and yellow ink looks more like a dark brown than a true black. Here's a nice wiki link for you on undercolor removal.
http://en.wikipedia.org/wiki/Under_color_removal
We're talking about devices here. Bringing theory into the discussion isn't going to change anything. If your shadow values all converge on the display, your detail is for all practical purposes clipped at that point regardless of the measured cd/m2 value.