As an investigator myself, I think it's a little moronic to go to Niger and ask the corrupt government officials there if the Iraqis had been trying to buy yellowcake from them. Of course this is the age of recreational drugs so things are being done a lot differently. It's kind of like going to a prison and asking the cons if they are really guilty of committing the crimes they have been convicted of committing.
He went there with an agenda and did superficial work. Do we know the author of the forged report for Italy? That was set up, knowing it would be found, in an attempt to hurt the President.