Why didn't the first 13 audit of the fraud case of Yuehai Railway Company find out the problem?

Cover up the facts.

In reality, the major shareholders or management of many listed companies often choose to cover up the facts and whitewash the financial statements when the company is in recession for the benefit.

False sales generate huge accounts receivable, and overseas head companies borrow money from foreign banks to buy these accounts receivable or credit-linked bills derived from them. Cleverly convert accounts receivable into cash in the account.