Multiple Layers of Wall Coverings
These pictures demonstrate what can happen when moisture gets trapped between multiple layers of building materials. In this case moisture had soaked up the drywall and was stuck between the studs and the paneling which was used as a finishing material. When this happens removal is the only option.
In the specific circumstances of the pictured job the water had soaked into the affected materials long enough that the carpet and pad had to be removed as well. Once the materials were dried out a local contractor came in to finish the reconstruction to help make it "Like it never even happened."