FWIW, according to this site, he had a transplant:
http://hairtransplant-info.com/best-celebrity-hair-transplants-pictures/There are a lot of gossip sites that are "outing" balding celebrities. I realize it's a crappy thing to do but the good thing about it is that it allows the rest of us -- who may be trying to hold ourselves to unattainable standards that Hollywood and the media tell us are ideal -- to realize that celebrities are facing the same issues as the rest of us, and that their "perfect" hair, skin, whatever, is an illusion in more cases than we realize. At the very minimum, a lot of stars use that fake "hair in a can" thickening stuff which can help cover up thinning areas of the scalp. Like rugs and plugs, it can look OK on film, but not if you see it up close and personal.