I can only take him at his word, Tom, when he tells me he "enjoys it more every time he comes to visit".
Having had it happen to me, I think you're entirely right that the course gets to you once you make one error. But I think that part of the deconstruction is that instead of hitting the perfectly manageable shot that is available, you try to do too much in an effort to make up ground - cut off too much of the tee shot on 6, go for a tough pin on 8 because you have a SW in your hand, play for a far left pin on 13 - and make even more doubles and triples.
With such wide fairways and a good number of holes that are short for their par, and with many greens not having wild contours, I agree much of the difficulty lies in the severity of the off piste areas and the psychology of knowing there is ample room to hit the ball, but that if you miss that area you're in hell.