I'm wondering if I misread this from the very start? If you are throwing a left hook, from a typical stance, your wt would go to the right leg, and the left foot would pivot inward- exactly like grinding out a cigarette with the toe. That pivot enables you to get the hip and shoulder turned all the way through. When throwing the hook, in order to get wt into the punch you have to shift it to the right foot and torque the left hip and shoulder to the right.
When throwing a right hand, from a basic stance (with the weight @ evenly distributed between left and right legs), the eight has to shift up to the left leg; the power comes from the turning of the hip and shoulder through to the center. That is why you don't put wt on the front foot when you jab- the majority of the power in a jab comes from pushing off with the rear foot, much like a fencing move. When throwing the right, the waist twist is essentially driven by the sharp inward pivot on the right toe.
The back foot provides the force due the fact that without its turning forcefully inward the hip can't turn as far as it should. But at the end of a right hand punch the wt has to be on the left foot- and thus the eternal boxing axiom of "always hook behind the right" as it brings you back to square so to speak.