If the short sale goes through that means the bank accepted the offer and escrow begins.

Sometimes the banks accept, sometimes they counter the short sale offer. It depends on a variety of factors. The bank does a bpo and an appraisal. They also may or may not factor in the costs of continuing to hold the property. Property taxes may incentivize the bank to accept the short sale. The last thing a bank wants to do is lose a home due to a tax default.

You just never really know what the bank will do. Also I keep saying bank but in reality the investors holding the paper give the short sale negotiator the thumbs up or down.