Recorded.
It was quite a surreal experience; first I spoke to Annabel who I'm guessing produces the show (she was the one who asked me if I wanted to be on the Lost line), who said that she'd put me on hold. Then there was a two minute interval where Annabel was asking someone how to put me on hold, so I could hear everything Iain, Paul and Tom were saying, which included something about "benevolent Sawyer" not being good and Hurley being the leader of the Others (that caused Annabel and everyone else to laugh, if I remember).
Then they introduced me, and let's just say I made an auspicious start where I may have accidently messed up my facts. Anyway, I finished my theory after what seemed an age...and thankfully, Iain didn't say it was stupid. Instead, it was "complicated, but there's a nugget there". Iain then wrapped it up after Annabel told them that the second email wouldn't be on it because they were running overtime. He finished it with his "Namaste.", and then it ended, and just before I got cut off I heard Tom say "you always do that..."