tell you the exact cause of the settlement in the first place. Normal consolidation and settlement after construction isn't a good enough answer.

Are there cracks in the sheet rock? Did the homeowners try to conceal cracks? Do the doors shut or do they stick? Have the wear marks on the door striker plates moved? Are there cracks in the exterior stone/brick? Or is there separation in the siding? Are there cracks in the slab where the floor slopes? Is it built on clay soil?

If you answer yes to any of these questions then I'm willing to bet that the house is still moving. And then the question is why?