I'm not quite sure what your question is. Clearly, getting the coping fixed is a good idea; and it's certainly a better idea for you if you can get the current owner to pay.

If you're asking, can it be an ongoing problem if there is no movement or expansion joint between the deck and the top of the pool wall (ie, coping or whatever) the answer is yes. It's a problem I've written about many times.

Also, I'm not from TX, but I know some parts of Texas have problems with soil that expands and contracts when the moisture level changes. If that's true in your location, getting control of the movement problem is even more critical.

Ben / PoolDoc