As others have said, those stats include us, as well as the MD/PhD students, who also get a free ride (and their living expenses as well).
I obviously don't have access to the stats, but if I had to guess, I'd guess that the majority of Case students are not paying the average indebtedness. Instead, most people are probably taking out almost no loans, or else paying close to full price with loans. In other words, rather than the debt of individual students following a bell-shaped curve, it's probably bimodal, with most people at one or the other extreme, and some people with partial scholarships or partial grants in the middle. Unfortunately, knowing the mean indebtedness really doesn't help us figure out what the mode(s) of indebtedness are.
I'd also argue that you should not make any decisions one way or the other until you get YOUR individual financial aid package. It doesn't matter if every person in the whole class except you pays full price--if you're that one person on a full ride, then your indebtedness will be very low, and in that case, yes, choose Case.
More generally, my advice is to be pragmatic about the whole thing. Wait to see what each school you're seriously considering offers you in terms of grants/scholarships. If you're basically getting full loans at expensive private school A, and you have an acceptance at your state school or elsewhere with a significant scholarship, then you should go the cheaper school unless leaving Cleveland would cause you a significant financial or personal hardship. For example, if you own a house in Cleveland, and your spouse has a well-paying job there, and you'd have to be separated from your spouse and kids in order to go out of town to the cheaper school, then it might make sense to take on the extra debt for personal reasons. But if you're a traditional student with no family and no job, there's no good reason for choosing Cleveland over any other city, and you should focus on minimizing your debt. Just my opinion--obviously you can do whatever you want.