This story on the alleged "Bin Laden hit" is completely unsourced. Note that neither the name of this courier, nor the names of the US officials making these accusations actually occur anywhere in this article. It simply links to the name of an organization, Harakat-ul-Mujahideen which is alleged to be an asset of Pakistan's intelligence agency.
Pakistan is the ground gateway for any and almost all goods and military traveling to Afghanistan. Should the Pakistani government decide to close all routes to Afghanistan, there is no really practical way to accomplish delivery of goods and military personnel here.