The extract from the interview relevant to St Helena is this bit, in which he bragged about how 'successful' the airport project had been:
"We decided we would build an airport on St Helena. £200 million and I said ‘never before has this department spent this money on an infrastructure project, nor has any infrastructure project been handled, you know, at such a distance. I therefore require someone who can advise me on what constitutes a proper, fair and as far as possible, risk-free building contract so we can avoid all the overruns. Someone who can oversee it, to make sure that it has been implemented as per the contract’. And as far as I know, that has gone absolutely brilliantly and I think a lot of that is down to the absolutely rigorous monitoring and drawing up a very, very tight fixed-price contract in the first place, with no variables which suddenly hit you in the gob and add £30 million.
So I think that has been a success. It has been an amazing project. Whether there will be any planes going to the airport later is another matter. But actually that was part of it, an air services contract. You know, you have got to have the building contract, the safety contract, the accompanying, if you like, hotels, accommodation for the supposed tourist benefit and an air service agreement and fuel, fuel tankage so all of these things had to come into a strict and big picture to make it all work."
Duncan was Minister of State for International Development from 2010-14, and he apparently only covered certain parts of the world that he preferred, which excluded Africa, but did include the Middle East, Palestinian Authority, Yemen, Bangladesh, Burma, Nepal and the Overseas Territories (St Helena is one of these "overseas territories"). He received a knighthood in 2014 for his four years service as a minister.