What we're seeing here is an attempt to subvert justice, an attempt to subvert the rule of law by those that are bent on attacking honorable citizens of Iraq who are trying to see that justice is done, whether it be on the prosecution side or on the defense side.
There was a security consideration. If they can take over and they can move to intercept and otherwise disrupt those who are bent on attacking the transfer of sovereignty, then that's one more blow against the terrorists.