This is the Al Capone method.
Trump probably goes to prison for tax and financial fraud. His trouble with financial claims and taxes are that they leave an unambiguous audit trail. Usually, he denies everything because he avoids writing his own instructions down: blame the attorney, and so on. But he has to sign his financial disclosures and his tax returns.
It appears he thought there was a complete disconnect between the valuation of his properties for tax and borrowing purposes. But his signature will connect them. And it sounds like there's going to be a gulf between them, with Trump the fraudulent beneficiary. In essence, his wealth is built from defrauding taxes from the government and security from financial institutions, as well as whatever he had from Russia.
No wonder he hid his tax returns.