My only thought is that he's still pretty young and if it wasn't the carpet, it probably would have been something else! I still crated Rookie at that age, but when I did start to leave him out of the crate, I did it gradually. He was gated in the kitchen and only left for very brief periods at first. Then we worked our way up from there. He's 2-1/2 and he still doesn't have access to the entire house when I'm not here. The bedrooms and my office are still off limits unless I'm actually in the room with him. That might sound extreme, and I'm not necessarily advocating that you go that far. But maybe start by giving him access to one puppy-proofed room when he's alone. Then see how that goes.