I wouldn't have expected them to do anything other than what they did because both the Manufacturer and Air Nelson told them ( through the QRH and verbally ) that the gear was down and locked. The manufacturer was adamant that that the gear was down and locked if three greens showed on the backup system, they designed the system, they tested the system, they have monitored the systems performance through many incidents and accidents while sitting at desks with no fuel induced time pressure. If I was the Capt of that flight I would have felt confident that they were correct.
I fly 737 classics and NG's, in the classic we don't have a back up light system but in the NG'S we do. The NG QRH says
: If a green landing gear indicator light is illuminated on either the centre main panel or the overhead panel, the related landing gear is down and locked.
Our company also actively discourages tower fly-bys as well. Can I trust that Boeing has done a better job of testing it's systems? Shall I do a fly by if I have three greens on the standby system? Knowing the "Pilot -Error " mentality of NZ accident investigators I think I will if I'm in Auckland.