I think you are right. A game is being played here.
Everyone in the know, knows what happened, but there must be reasons for it to be played out this way.
Maybe so the Russians aren't embarrased by the story. maybe the "blackmail" which will prevent them helping Iran too much, maybe the lever to get the Syrians out of Lebanon etc.
ie "We know where the weapons are hidden and if they get found in territory you control nothing will save you".
I think you hit the nail on the heed. If you're right, Pres. Bush took a very big political hit on the WMD issue in the run-up to the election. This is a true "profile in courage".