It will have to be a perfect forgery and the perfect crime, the Rats haven't been able to pull that off too successfully. They try like hell with the aid of their accomplices in the MSM, but the truth always surfaces.
Oncde the vault copy is opened, the state of Hawai’i may still have control over the physical document and it may never leave their grasp thus authentication beyond Fukino’s word may be impossible. I cannot think of a legal precedent which would force the state of Hawai’i to present the document for expert authentication.