Not sure why person would not have called ethics line or even complain local govt HR authorities(if any). The allegations seems to be definitely a harassment if the person was not paid for work to be done outside working hours(not very clear if the person was paid for midnight calls). Not sure now but when I worked in Microsoft as customer support. They really really took care of the employees, it was a cost centre and there were call centre metrics in place but employees were treated really well. Leaves given as needed, paid for extra work and an excellent customer centric but a humble culture inside the org. The dev teams appreciated inputs from support and vice versa.