You can see from the responses that a short sale does require a little more knowledge than the average transaction. We as parents can only do so much for our children. It's really up to your son to be engaged in the process. So encourage him to make sure it's handled by a professional full time agent. Plus I'd recommend interviewing more than one to get a understanding of exactly what it's going to take to get the job done.
I do service the area and would be happy to give my perspective on the market value and see what the likely hood of a short sale would be for this property. Hope this helps!