It is some well-known fact that there is the unit element in $K^{-2}(point)$ whereas there is no unit in $H^{-2}(point)$? Where it is come from?
For details I add the link http://pages.uoregon.edu/ddugger/kgeom.pdf , the last lines of the page 169. The author fixes this fact in the way that I also don't understand. Can anyone explain what is going on there?