PS4 Controller Thumbstick rubber peels off and R1 button gets stuck

I noticed this stuck R1 button on two demo units in two different stores. The first store, had only one demo unit, the second store, this controller was in the first unit you see when you get in the store, so the most highly trafficked unit. The other demo units in the second store didn't have this stuck button issue nor did they have the thumbstick wear and tear. The thumbstick seems to use a thin layer of rubber which is easy to peel off. The R1 button gets stuck the same way in both the highly trafficked demo units, simulating a long stress test that Sony may not have achieved. The less trafficked demo units didn't experience this issue, yet. This leads me to think, that this problem will surface post launch as many gamers will run into it after long hours of stress testing the controller.