I've not listened to the programme yet but as LWaB says, this isn't the first time he's covered audax - he did a feature on the 'Uts a while back, and rode the Up The 'Uts 200, iirc.
I've corresponded with Jack Thurston via twitter on the subject in the past and he definitely seems keen, though extreme endurance doesn't appear to be his thing. Still, he's a useful advocate and AUK would do well to exploit his enthusiasm.
The Bike Show is always interesting and well worth listening to whatever subject it's covering.