This case is just that, a case based on facts. Donald Trump wanted money and applied for loans based on the value of real estate assets. As a "Real Estate Mogul" he knew the real value of these assets. He told the banks that they were worth more and convinced them through manipulation of markets. These facts were written on paper and filed in official transactions. For example, in one case he said his personal condo which is 10,000-square feet was 30,000-square feet. He knew this was not true, ergo fraud. This is just a small case of hundreds of millions of dollars in fraudulent loans he "secured."
The only question that really matters is, "Why?" Did they make a forgivable mistake dozens of times, or did they do all that has been done on purpose?