Users from One of the package approver group (aprvgrp1) was able to approve the package against the Quorum size . Though the quorum says '1', any number of people from the same approver group are allowed to approve the package, which is what happened here with this package.
Though the second approval job failed with a return code of 12. The 'APPROVER GROUP DISPLAY' panel shows that the package is approved by both. (See picture attached below)
Release : 18.0
Component : CA Endevor Software Change Manager