The only time there is a property valuation issue is if the owner of a property OVERVALUES his property in order to get a better interest rate on his loan.
Anyone is free to undervalue their property to their bank. That's not illegal. For example, Trump told his banker that his 10,000 square foot apartment was actually 30,000 square feet, and then blamed this "error" on the appraiser who included roof access and elevator shafts in the square footage.
Donald Trump builds and sells condominiums for a living. He built his own apartment in Trump Tower. Do you mean to tell me that the guy who built that apartment doesn't know down to the square INCH how big it is? Or how the square footage of condos is calculated and costed?
You have to be wilfully stupid not to realize he was lying about blaming the appraiser.