pakistan didnt know bin laden was there, nor did they know the CIA was there
http://www.nytimes.com/2011/05/06/world/asia/06intel.html?_r=1&hpThe C.I.A. had Bin Laden’s compound under surveillance for months before American commandos killed him in an assault on Monday, watching and photographing residents and visitors from a rented house nearby, according to several officials briefed on the operation......
The C.I.A. surveillance team in the rented house near Bin Laden’s hide-out took pains to avoid detection not only by the suspected Qaeda operatives they were watching but by Pakistani intelligence and the local police.
Observing from behind mirrored glass, C.I.A. officers used cameras with telephoto lenses and infrared imaging equipment to study the compound, and they used sensitive eavesdropping equipment to try to pick up voices from inside the house and to intercept cellphone calls. A satellite used radar to search for possible escape tunnels.