Sure, and that would be a fair criticism, to say, "is there a version of this that's more intuitive and easier to read with the same load on the server?" But the interviewer (assuming the OP faithfully represented the exchange and the domain) is insisting that the query does not do what was asked -- when it does -- and is saying so based on the interviewer's own incomplete understanding.
That's not a good reason to reject a candidate, even if there might be other good reasons in this case.
That's not a good reason to reject a candidate, even if there might be other good reasons in this case.