Did he get into anywhere ranked higher?
Cornell, UT and Northwestern are all amazing schools. You ought to be extremely proud of your son and I'm positive he has a very bright future ahead of him. The problem is, these schools all place much much better in their respective regions than they do across the nation. He'll have little problem getting a job in that region, but as soon as he goes to look for a job elsewhere, he will give up that advantage. The reason I asked if he got into any other places is that only the top few schools (Yale, Harvard, Stanford and maybe Columbia) don't lose their luster when you look elsewhere. Otherwise, trying to decide where you want to go after law school is EXTREMELY important to making your decision on where to go to law school. Almost always, it would even be better to go to a lower ranked school in the location you want to stay in as opposed to going to a higher ranked school in a different region.
All of this being said, I do understand the desire to keep your options open and not be committed to a location you are not sure you want to stay in. Trust me, I know from personal experience. I wish this wasn't the case, life would be a lot easy for both your son and me.