In many federal civil lawsuits discovery is not allowed. It's at the discretion of the court wether it is allowed at all, and if so, how much. And federal courts give the federal agencies an undue level of discretion with regards to "expertise", affidavits, etc.. even when those are contradictory to established fact or even previous statements by the same agency.
In a recent and ongoing federal civil case the Department of Justice provided affidavits that supported a policy-based set of decisions, from the person who was most involved in the creation and execution of that policy. Then turned around and in a subsequent set of affidavits basically said "Oh wait, we changed the policy to the new policy before that, and the new policy violates the law less" --- and the court accepted it. The agency says it did not even know what it's own policy was, and this was coming from someone intimately involved with the creation and execution of that policy.
You can't make this stuff up.
