The Supreme Court has reserved its decision in the case of a senior pilot who claims he was discriminated against because of his age.
David McAlister claims Air New Zealand discriminated against him by demoting him from being a Boeing 747 captain and flight instructor to the lower rank of first officer when he turned 60 in 2004.
Mr McAlister's lawyer said Air New Zealand had an obligation to accommodate his client, but the airline's lawyer said international rules prevented Mr McAlister from carrying out all his duties.
The Employment Court earlier found Mr McAlister had been discriminated against on the grounds of age. However, the Court of Appeal subsequently ruled in Air New Zealand's favour, saying that under international rules Mr McAlister was treated no differently to any other captain.
On Thursday, lawyers for the Human Rights Commission told the Supreme Court that legal decisions relating to discrimination must be written in a way that the general public can understand.
They told the court that, unless there are simple solutions to discrimination issues, people might not understand and might, therefore, be diffident about asserting their rights.
Earlier, the Deputy Solicitor-General told the court the law relating to age discrimination is not straight forward and it has been a difficult area for judges in several jurisdictions worldwide.