This is not the first time teams like this have been sent in to rub out a house full of bad guys jihadis.
The target/targets are given code names along with the particular operations.
The Seals likely weren't even told they were on a mission to kill "Bin Laden". There was no need to make them part of a conspiracy. They simply did their job and went home. The civilians at the top took it from there.
The operational levels of our military had no ability to participate in a conspiracy to "kill" Bin Laden (or to kill "Bin Laden" if you understand the difference).
AV
http://www.politico.com/news/stories/0511/54151.html
Officials described the reaction of the special operators when they were told a number of weeks ago that they had been chosen to train for the mission.
They were told, We think we found Osama bin Laden, and your job is to kill him, an official recalled.
The SEALs started to cheer.