DJ said it never occurred to him that he was in a bunker. Let's see, I'm on a golf course with about 1200 bunkers, probably close to 100 of them on the 18th alone. My balls not on grass, but sand or dirt. There's flyers up in the locker rooms, bathrooms, and the local rules sheet has the bunkers as it's number one item. I think the fact that it never occurred to him that he was in a bunker has to go down as one of the biggest mental errors ever to have cost someone a chance at a major.
In my opinion, only DJ and his caddie are to blame. Not the PGA, Pete Dye, or a rules official.
Kaymer kept the cool head, made the clutch putts, and is the true Champion.
Maybe it's just me, but what a mess that area was. Don't they have trash cans in Wisconsin? I was at the Open in St. Andrews, and didn't see so much as a gum wrapper laying on the ground.