How does an expert use his expertise in order to find out financial difficulties faced by the company?

Have alternatives, look for other options quickly to save time. You must always have back up and learn to multi task and prioritize all tasks to be completed according to their sense of urgency.

Debtors Aging.  Deteriorating Debt to Equity. Poor capital allocation. Increse in laon defaults. 

When the timely requirement of the funds exceeds availability and all resolving means are exhausting even after proper planned efforts.