I’d think it largely depends on which state you are in. I seem to recall that the ACT had disclosure statements. But even there, where it comes down to purchasing a property, it’s largely a case of caveat emptor (buyer beware).
Once the settlement is made, it would be difficult and costly to prove that there was misrepresentation over the defect, and to receive compensation.
If your settlement agent was negligent it is possible you could claim restitution, but wouldn’t like your chances without a major fight through the courts.
Sorry to be so pessimistic.
DaveB