During the process of the short sale, you will need to provide financial information to the bank that is as in-depth (if not more so) than you would if you were applying for a loan to buy teh property in the first place.
Additionally, the bank will look at your letter of hardship. So, if you are currently unemployed, behind on your bills, and struggling to just keep the power and water on, then the bank would be much more likely to forgive the debt and move on. It would not be in their best interest to get a judgment against you (blood from a turnip).
If, however, you have the financial assets that they could possibly recapture their loss from, they would be much less likely to approve the forgiveness of the loss.
I have seen many different outcomes to short sales over the last few years. They include:
1. denial and eventual foreclosure
2. full approval and forgiveness of outstanding debt
3. partial approval where the seller and/or buyer contributes some money
4. approval, but requiring the seller to sign an unsecured note to pay off the outstanding balance
A lot would depend on the financial institution, if they have it insured (Fannie / Freddie), etc.
Because it's not a primary residence, B of AZ might very well be able to persue your personal assets to make up the deficient amount. I would speak to not just an attorney, but to a bankrupcy attorney because they would be more familiar with these situations and what your options are.
Get an attorney,