EPAM Systems interview questions

The interview process was smooth. HR kept me well informed. My technical interview (which is basically a techno-managerial discussion in case of project managers) went great. All the questions were around Agile and ITIL. I managed to correctly answer more than 90 percent of the questions asked. I was more than confident that I would make it through. But I received a call not more than 1 hour later stating I am not selected. I was surprised. One thing I understood from the rejection comments was that 1 question decided my fate and that was DOD (Definition of done). I got a little confused and besides it being an interview from Project Management skill, this became the deciding factor. I mean I was never asked about the project planning or stakeholder management. Thinking back I am not even sure which skill the interview was for? I wonder if they were looking for a scrum master. Even if they did, how did this question have so much weightage?