I was not stating it a as fact, but something that IMHO Al M. (or me, or any cable believer BTW) must accept. When we change cables the differences in signal are most fo the time very low - some people state around -130 dB - and we claim we listen to them. These differences are much lower than the lsb.
I accept this too but right now I'm not seeing how this might relate to digital audio theory. Are you of the view that digital audio is incapable of conveying signals smaller than the LSB?