If anyone will receive backlash, it will be al-Sadr, and he deserves it. He spoiled the fun for the Kurds, embarrassed Maliki and other Shias, and humiliated many Sunnis.
He overplayed his hand this time (once again), and one can hope he will pay the bill for all his mischief and mayhem sooner rather than later.
That would make sense, especially since those in the room were taunting Saddam with Mookie's name, right before the execution.