Maybe I'm just too cynical, but I don't believe the story about following the messenger who led the CIA to bin Laden. What I suspect is that after a good few years the CIA is now well and truly inside al Qaeda and that there was some definite, hot tip from a live body high up in the organization which led to bin Laden.
Funny enough, I'm also more willing to give Pakistan a bit of a pass than are most Americans. Yes, bin Laden was living near a military school and not far from Islamabad. Yes it seems kind of unlikely that he lived there for so long with no one in the Pakistani government or intelligence services knowing he was there. BUT, that same government and intelligence service delivered Khalid Sheikh Mohammed into America hands, although that was 8 years ago. Have things changed that much inside Pakistan? Maybe they have. Besides, I don't believe the story we've been told
The other thing to consider is that we didn't want bin Laden alive, which is what we would probably have had if Pakistan had moved in to capture him. If bin Laden was taken alive it would have meant (a) he would have to have been moved to some secret prison, (b) no formal announcement of his capture and (c) either a military tribunal to convict him or a circus trial where the host city was under constant threat of attack.
No, bin Laden could not be taken alive, which means from September 11 onwards the United States was doomed to lose the good opinion of Mary Robinson and the Archbishop of Canterbury. A tragedy.