Think of impact as a story rather than a one-line joke. That is, thinking of impact and low-point as the same does not necessarily mean they are. Impact is the point of collision and low point is the center of the orbiting clubhead.
Go further into the paragraph...."There is no accuracy for any procedure unless the HANDS execute a definite Hinge Motion."
Many times low point is not the shoulder in putting, nor the spine. Often times players will cause their wrists to arch or bend and the putterhead wil get to the WRIST's low point. The stroke has just become manipulated and complicated.
For reverse loft, a player could lean the shaft forward a great deal and move low point forward (aiming point) with a standard lofted putter. Hooding the putterhead in effect.
