You can also have a prosecutor or judge sign off on it. Trust is the easiest way though. Wish I would have gotten mine sooner.
Can't sue him because there's nothing that requires him to sign. The ATF says that a CLEO sign off is required for paperwork done by an individual but there is nothing saying that the CLEO is required to sign. Being that you have several alternative routes, you would have to exhaust every one of them before the ATF would try to work out an alternative.
Actually, Indiana Code says that a government entity may not regulate firearms, ammunition, or firearms accessories. To me, this sounds like Treachman is regulating firearms.