Accenture Senior Java Developer interview questions

3 rounds in total, 1st round was technical , 2nd was HR and the final round was messy not be judged what kind of round it was. First 2 rounds were very professional and 3rd round happened after 2 weeks of gap & 5 times rescheduled, the interviewer and HR joined the video call 15min late and the interviewer spoke for 2 min and disconnected the call. he only checked if I have DELL BOOMI experience which I have no where mentioned in my profile or prior rounds. After 1 hour I received email mentioning I am rejected, I was disappointed on the 3rd interview panel. If the decision is to reject the resource what is the point in making to wait for 2 weeks even after HR round.