Hey Johnny,
If you notice closely, the main traveler is all the way out to the starboard (leeward) beam which means they probably sailing at least on a beam reach, not withstanding the fact that it is unlikely that they were doing 20Kts close hauled. Trapezing on the stern may have helped prevent this pitch-poll episode but remember, that was a H16 they were sailing. Even so, H16's don't have a monopoly on pitch-polling. Check out the video below, if you haven't already seen it.
http://www.wetasschronicles.com/HobieCartwheel.wmv
Second, I think the camera was on the "Head-Cam" of the helm. Additionally, he probably hung on to the windward hull (which is the one that's usually out of the water (7 feet) when you cap) to keep his camera from getting wet. I've lost a camera capsizing. It's quite an expensive luxury.
Happy Sailing,
David