How many people has the US government found that they can prove were involved in the planning and executing of a the co-ordinated hijacking of five aircraft???
None that I know of! How could that be?? They have the most powerful military and intelligence gathering force that the world has ever known and yet they can't find some guy in a cave!!
In any case I prefer forensic evidence to water boarding but I agree with your point regarding Ockham's razor... If it looks like a controlled demolition then it probably is a controlled demolition. If it looks like a building is exploding into dust the building probably is exploding into dust.
