The mold in this house was mostly from the fact that the windows (nice mahogany windows) had been improperly installed. The leaks below the window sills caused mold that was concealed inside the walls.
Does the word "lawsuit" come to mind?
I know the house is over one year old and outside the general contractor's normal one year warranty period, but there is a term called "Latent Defect" that addresses items like this.
'course in this case, the buyer probably doesn't care about minor things like that. He apparently only wanted the lot (and got it!!!!)