Since this step is sequential with defect triggering, it is important to note that the effective working size for this activity is not larger than the preceding step in the defect reporting sequence. The erroneous behavior may not be critical, perhaps only causing an inappropriate message or formatting in a log file. System redundancy may mask errors. How the defect manifests itself. If a program fault causes abrupt program termination, the user will probably notice.
Someone is sure to notice spectacular failures.
Motivate users to look for defects. Remove the human factor.