ARTICLE: Iran's Top Leader Endorses Election, By Thomas Erdbrink and William Branigin, Washington Post, June 20, 2009
You knew this would eventually be the charge and so you didn't want to give the Supreme Leader any unnecessary ammo. Why? Because when the charge was inevitably made, it would seem that much more laughable to outsiders and insulting to those who protest within Iran.
Not a strong move short of the full investigation. It signals serious fear on the part of the Supreme Leader. He's afraid of things unraveling and wants to end this thing now with a strong statement.
As I have indicated before, I don't think the opposition is nearly organized nor mobilized enough at this point to win (one can always be pleasantly surprised). The key will be the staying power and new growth in the months ahead.