Fraud vitiates every transaction and all contracts. Indeed, the principle is often stated, in broad and sweeping language, that fraud destroys the validity of everything into which it enters”–37 Am Jur 2d, Section 8.
FRAUD VITIATES EVERYTHING” (FVE) is the legal principle that, once it has been shown shown that one party has lied or committed a deliberate misrepresentation, their whole case is thereby compromised and no longer defensible in a court of law.

So they think...