To be honest Perry no I have not listed a short sale yet. Perhaps sdr or Jim has though.
My guess is that the lender pretty much makes the call and instructs the realtor 100%. I have represented buyers for REOs. In that process the lender had a broker that handled the negotiation but the portfolio manager for the lender called the shots. We tried negotiating and they played hardball. We got a good deal but only because they priced the home to sell very aggressively. I do know that the short sale process is more involved and it “appears” to me that the hardest part about it is proving the hardship case to the lender from the sellers standpoint.