While they accepted Far North Holdings lawfully occupied the land on which the airport sat and were entitled to issue a trespass notice, the six said they honestly believed they had "co-existent occupation rights".
Their lawyer, Annette Sykes, said Cabinet decided to rescind the transfer of the aerodrome to the Far North District Council in 1994 in favour of a lease pending resolution of the Muriwhenua claims.
Since then, she said Ngati Kahu's ancestral connections and the lease arrangements in favour of the council "co-existed" pending final settlement, albeit at all times limited by the Treaty obligations of Maori and the public good.
Professor Margaret Mutu and Reverend Lloyd Popata outlined the whakapapa and marital links of each of the six defendants and their connections to the airport land.
Justin Wall, appearing for police, said it was very difficult for the six people to argue honest belief on any basis other than a misapprehension of their legal position.
Their failure to leave when warned was not an assertion of a right to occupation but rather a political statement designed to obtain the government's attention, he said.
In dismissing the appeal, Justice Matthew Muir said a person's belief needed not be reasonable, it simply must be honestly held.
However, he said it must be a genuine belief in facts or circumstances which would make their presence lawful despite being asked to leave.
The judge said neither Professor Mutu nor Reverend Lloyd Popata purported to speak to the mind of the defendants.
He said the duo's evidence established the defendants' strong ancestral connection to the airport land.
"That may have given rise to an honest belief in Ngati Kahu's right to have the lands ultimately returned to them but it does not establish an honest belief in a legal right of interim occupation.
"What has occurred in this case is in my view a disjunction between the evidence called in support of the alleged honest belief and the nature of the belief asserted on appeal," Justice Muir said.
