I don't know.. He may not have been on an HT (did he say?). He was probably on a more powerful radio, with a decent outdoor antenna mounted. Just a guess.
Darrel (Of Mile High Pizza fame), is sitting in his vehicle I assume, at the top of table mountain, which is why he's able to talk to a lot of people. I'm not sure if he's using the fancy portable repeater, or just his HT or a mobile radio.
But that's why we do the simplex test.. its good to know who can and can not talk to each other, and its good to know who (outside of the area) we can contact, if needed