There are many reasons why it may take up to 7 months to get a short sale to close, some of which are not known to the general public, and those not in the lending business. I will note that as Bobby J said, not all take up to 7 months. Some lenders have been quick to make things happen.
I'm not a lawyer. If you have any question whether or not it is legal, contact an attorney.
To comply with the MLS rules, a Realtor cannot list a property as a short sale without it officially being a short sale. There is an addendum to the listing agreement for short sales.
It was obvious for a while, that many agents listing properties, were uneducated regarding short-sales, foreclosures, and REOs. Not too weird, because it was new to us all. However, there are some of us who have chose to talk to attorneys, title companies, etc, and attend classes educating us to the ins and outs of these types of transactions. (I'm not talking about the classes on how to get rich by listing short-sales. That is a class which I never had interest in attending.) For a while, many people were using the term, "short-sale" strictly as a marketing tool. The MLS quickly came up with definitions and rules regarding these new types of sales, and that tightened up things quite a bit. I think Bobby J gives some good recommendations on questions to ask your Realtor before giving them your short-sale business.