I finally got around to watching this on "Dave" tonight. The caves were impressive, but much of the "analysis" seems pretty poor to me. I really could not see that the pile of breakdown represented a man made dam, and the rationale for claiming the cave was 23 million years old seems tenuous at best...
Saying that, it is great to see that the immense potential of lava tue caves in Saudi is starting to open up. I can recall a presentation at the volcanic caves symposium in 2006 which included following a line of skylights for over 40km by helicopter, but the presenter being frustrated by not being able to get permission to explore on (or below) the ground.
Lots more really interesting stuff is going to be uncovered here I am sure, and hats off to Steve Backshall and Co for highlighting such an exciting place.