>>8788256lets be honest
if you find Osama you sit and wait
Why? Observation, see who goes in and out (who to kill / track). The fact he is still alive maybe makes them think he isn't being tracked/observed.
Basically if you find a leader of a terrorist org, or former leader. You don't go in guns blazing day 1, this was probably an operation lasting years. First you milk him for any possible links, then when done you clean up (kill everyone associated with him and him).
I really doubt this was the extent of the ops and it was probably a lot bigger operation. Obviously killing him is a goal, but it's not victory in the war.