It could be that the applicant couldn't prove he/she actually studied - failing to pass the interview.
But just for information, the Language Institute in CMU is not part of the University; it's a separate Institute, with its own rules etc. Almost as a private school auspicied by CMU.
And when I asked there, I did not feel very confident about the quality as a proper school for ED visa, as the schedule was just 2 days a week and some free weeks every 2 months...
thing is that they don't like the people living here under tourist visas or exemptions - but they like and push into the Elite Visa. It's not guaranteed that they let you in again, but at least I'd say you have a good card to play by showing them that you're on a new exemption only because your Elite is still processing.