We rely on Experts for their knowledge of specifics, and if relevent specs aren't known to them, perhaps they should have known?

Legal entanglement doesn't require fraud with its intent to deceive. Mere negligence (unintentional misrepresentation) is good enough if damages result from reliance there upon. And the opinion of your "expert" in a legal setting is readily countered by that of my "expert". All it takes is money.