Just try thinking thru what you are saying. First of all, if the wood is treated or is naturally rot resistant like cypress or cedar (which is pretty likely for landscape blocks), it does not need to be painted for outdoor use. If the wood is not treated or a rot resistant species, then painting the exposed side(s) of wood in contact with the ground does exactly nothing as the non-exposed sides of the wood which are in contact with the ground (which will not be painted since they are buried) are what will rot first (since those sides will stay wet far longer than the sides exposed to the air). If the wood has never been painted and is just landscape blocks, then there is no lead paint issue and no health, safety, or structural soundness issues involved and I stick by my assertion that the appraiser is an idiot.