Regan's contract runs until the end of the year but he has New Zealand's two leading swimmers in his stable - Lauren Boyle and Glenn Snyders.
Freestyler Boyle led the Olympic team with two final appearances, the only Kiwi to do so. She finished last in the 400m freestyle final and fourth in the 800m final, 2.4s off a medal. Breaststroker Snyders made the 100m and 200m semifinals.
There were few other thrills for the 16-strong team. They contested 20 events, with five personal best times achieved - two by Boyle, two by Snyders and one by the women's 4x200m freestyle relay.
Sparc, the predecessor to High Performance Sport New Zealand, had long claimed a medal and five finals would be SNZ's minimum required return to maintain the current funding - $6.6 million out of an overall high performance budget of $60 million in the last Olympic cycle.
In a further indictment on the national programme, Boyle spent most of the Olympic cycle in the United States, working towards a degree at the University of California, Berkeley. She was mentored by the American women's swim coach Teri McKeever. Boyle had been under the coaching of Australian Regan since May 2011 and continued to progress. She also made three of New Zealand's four finals at last year's world championships.
As the country's best swimmer, Boyle may consider her options elsewhere if Regan leaves but that might mean funding her future herself. Any plan she comes up with requires SNZ's stamp of approval if she is to continue to get government funding. It may be a Catch-22.
While Regan has produced the best results among local talent, home-grown coaches Hurring and Talbot have received considerable SNZ investment. They have been selected for the High Performance Sport New Zealand three-year coaching accelerator programme.
Hurring had the best result of the pair at the Games, coaching Gareth Kean to a semifinal of the 100m backstroke, where he finished last. Talbot is favourite to be appointed team manager at next month's short-course world championships in Istanbul.