The concepts that you never use in day-to-day basis is what they ask you in the name of level 1 interview. I really don't know even if someone from their own team would answer if asked all of a sudden. The interviewer had a set of answers in their mind and would say wrong to whatever approach you suggest, one of the amazing things the interviewer said was "You cannot use a column in 'ORDER BY' if the column is not used in the 'SELECT' statement". Overall, the worst ever interview experience in my career.
Please send someone who can actually thinks thru the candidate's answer before arriving at a conclusion.