How "compensating Errors" are a botheration from Accounting/Auditing point of view?

compensating errors are:

 errors in computation or in recording of accounting data, that is   balanced by an equal and opposite error

*- compensating errors do not show up in the total ( trial balance),

*- they are difficult to  find by statistical methods..

. 

Since compensating errors do not show up in the total, they are difficult to locate through statistical methods and that is why they are bothering auditors.

  errors equal in amount but opposite in sense that cancel each other