Here's the issue with the critique you are making in its own terms.
"Failing to declare a higher market value on a property ..." Stewart didn't declare any market value on his property, the county taxing authorities did. He has nothing to do with it. If Trump disagrees with his Mar-A-Loser valuation, he's well within his rights to tell the bank it's worth more (and Trump would be right in this). Of course, what Trump instead does is get an appraisal done regarding a property that doesn't exist (and inflates that). Which is the pretty obvious fraud there. He pulled a different con on the Trump Tower property ... just inflating its size. On other properties, he claimed there were development agreements for lots that didn't exist. Just one lie after another..
But if your property is worth more than the government decides to tax you at ... GOOD FOR YOU. You've done nothing wrong! And you pay less taxes. Good for Trump that the MAL value for taxing purposes is lower than the market value (it genuinely is, even with restrictions).
So everyone knows the actual facts on the MAL property. Trump made it into a "social club," so it can't be used as a single-family home (he does that anyway, but whatever). However, he must continue to admit members into his club. This massively lowers the value of the property, but also massively lowers the taxable value (which is what Trump wanted, at one point he couldn't afford the higher taxes, tho he could now). When Trump has it appraised for its actual value, he does so neglecting to appraise it as a "social club" (which it is) but instead as a private, unencumbered property (worth more).
The most amusing thing about this Trump case is - even if you think the case is total BS - his frauds are belligerently obvious. They aren't complicated, they are just easily disprovable falsehoods about property usage and size. The man is not a complex fraudster.