Accounting shenanigans are discovered from time to time, even in supposedly well managed companies. These have frequently been covered up by the management for many years and not been detected (or even suspected in many cases) by well qualified auditors, who have access to the companies' records and officers, and analysts, fund managers, financial press, etc who pore over the financial statements well aware of the frequency and consequences of shenanigans. It is highly unlikely that amateur investors will detect shenanigans that are missed by the auditors, analysts, etc and the only way for private investors to mitigate the consequences is to diversify their portfolio.