Because the employee did not perform the work steps. The decision to fix the problem by not informing the supervisor to check the accuracy of an error that is detected by the QA.
The employee does not perform the procedure. To fix the problem themselves by not notifying supervisors in order to verify the accuracy error is detected by QA.
Because employees don't work on stage work. Decided to fix the problem yourself without inform supervisors know to check the accuracy what the errors which are detected by QA .