I know it does suck. So alot fo the scams u see are short sale middlemen and such. One thing that is key for the short sale lender to approve the sale is that they always ask for a printout of the MLS listing. So the listing agent will put it on there simply to prove to the short sale processor that indeed the property was on the MLS.
Pretty much of a joke.
If the short sale lenders wanted to, they could eliminate all of this really easy. They can literally demand that short sale listing agents keep the property listed as active for a minimum of say a week or two. Similarly the short sale lenders can demand from each MLS that agents representing buyers can contact them if they had written a higher offer then what was actually accepted. That way they can bust listing agents that do this stuff.