have you ever seen a mortgaged real estate deal that the lenders did NOT require appraisals before making the loan -- so bank fraud is likely out -- do you think NYC (and other big time tax assessors) does NOT have full time appraisers on its staff setting the tax values -- so that door closes --
Now connect all the dots. You under value your properties for insurance purposes then over value them for lending purposes on the same properties you are taking out loans against.
Apparently risk insurance and commercial lending is something new to you.