NSR you make a good point. When I do represent the buyer I do go ahead and look at the other sales in the neighborhood to see how they went, if they were foreclosures or shorts or REOs. I do not go that far back though, mostly in the past 6 months. Also it is not just the solds but you have to look at the actives, pendings, cancelleds, expireds…Also the type of home and location has bearing on things. In some cases the homes that people are buying are in new developments (from builders) or are very unique properties, (rural areas) so the search comes up empty.
Also whether or not you could sue is something that would be up to a lawyer. Unfortunately the CAR listing agreement becomes the formal contract when you list a home to sell. When you are a buyer there is a formal Buyer representation agreement in place but it certainly does not spell out the exact tasks that your Realtor will perform for you.
You definitely, to be safe, should ask your realtor to specifically do this search for you.