USCIS does not have to push the FBI to finish your name check, thats correct. But the court can. If you name the FBI as co-defendant, the court can order the FBI to complete the check. If you win your case, the FBI has no other choice than complying. There is some recent legislation that USCIS and the FBI can use to defend themselves, but some judges have refused to apply it here (the Real ID act). If you are lucky and you get your order from the judge, you are good to go.