"He was unforthcoming as to whether he assigns higher grades toward exams closer to the top (closer to him) or closer to the bottom (further away from him), so the disclosure was not particularly helpful."
You can figure this out pretty easily. What is the correlation between grade and length of exam answer? If it's positive, then the top is high grade (bulkier answers have more pages, are heavier and less aerodynamic). If it's negative, then it's the reverse.