In the bad old days, when men were men and barmaids ate their young, it was usual and legal to go out to NLK without an alternate if the weather forecast allowed. We always calculated a PNR to either return to the mainland or divert. By PNR we had to be reasonably assured by the latest weather observations at the island that we had a very good chance of landing. PNR was typically about top of descent. Even so, sometimes it went wrong in the last 30 minutes and, having committed to continue past PNR, we were forced to either land by busting minimums or to divert with less than legal reserves. Those of us that went there often enough probably did one or the other or both at some stage. What we did know was NOT to persist with multiple approaches until a ditching became imminent. Better to miss and go somewhere inconvenient even if it meant arriving with only 20 minutes fuel. Fuel could always be stretched by shutting an engine down in the cruise and relighting it on final (done that).
After a few good frights and close calls, CASA saw the light and the rules changed to always require a suitable alternate for so-called remote islands. The two hours 'island reserve' mentioned elsewhere here no longer became a choice. In any case, two hours would get most aeroplanes to either Auckland or Noumea.
So, either the rules have been broken or there was an un-detected fuel leak. For the 'hero' status of the pilot to remain intact, I hope for his sake that it was the latter.