The only bad nonconformity it the one we do not know about. Understanding this fact is the key for leaders and their managers being careful not to create a culture that hides nonconformity.
Even so it is common for managers to demand no mistakes and to react badly to errors.
Leading organizations provide employees with management systems that help them to understand and fulfill the requirements. And servant leaders provide a management system to help their employees to eliminate the causes of nonconformity. They do this gradually, according to the 80:20 (or 50:4) rule, so they always start with the vital few nonconformities that cost the most.
Zero Defects (zero nonconformity actually) has to come with humble managers who take responsibility for their management system causing the nonconformity. Care and respect remain to most powerful parts of such management systems. It should not require courage for employees to talk about problems in doing the right work right.
These organizations welcome nonconformity reports to show where the management system needs further improvement to prevent failures to fulfill requirements. They know the only bad nonconformity is the one that remains hidden.