When I called the accession officer why I wasn't selected. She told me because of my lack of leadership. She told me that she praised me as "I would leave my sailors behind when s*** hits the fan" which really angers me. I even asked her during the interview if she had any concerns or comments about my qualification and she said no. I would gladly give up my life to the sailor/soldier beside me.
That would also help to a "N" but I had several with high GPA's with little leadership experience and they were picked up, I also had one with a lower GPA about 3.2 that had quite a bit of leadership and she was picked up.
Your lack of leadership may have been the deciding factor but your GPA wouldn't have helped..... we had a kid who's GPA was a little bit lower than yours, college athlete, leadership in fraternity, leadership in church, leadership in schools engineering society and had an uncle that was a flag officer in the CEC (gave him a LOR too), he was a "N", the accessions officer said they had too many guys that were all that and a good GPA, and they need to make sure they pick those that shouldn't have any issues getting into a Master's program.
CEC can afford to be very picky.