That's the weird part to me. Either they were completely cut out of this, or the State Department and White House only told the highest levels of their government and requested that they play dumb afterwards.
If they were asked to play dumb, it turns into a fake foreign relations disaster that builds an illusion of weakness where none exists. That fake schism might be enough to lure out some of the AQ sympathizers within the ISI, the Pakistani government, and the Pakistani military. Asking them to play dumb also allows them to avoid publicly collaborating with the US government in killing bin Ladin, which insulates the Pakistani government from some of the reprisal that they'd be at risk of were they to have been openly involved.