I would bet my paycheck that they're NOT PS'd. He is well known for some extreme sports photography. I don't know if there are other sites with a better collection of his stuff, but here's one he's working on that has some of his stuff if you click on "CLICK HERE" in this link:
http://www.freezefocus.com/ and you can see the pics above and other cool shots at Hans Rey's site
http://www.hansrey.com/latestadventures.htm