The pair were told by Air New Zealand in the meantime that they could replace the missing items and clothes on a like-for-like basis.
The Greens spent over $26,000 replacing what had gone missing and recovered $1900 on a travel policy they had taken out.
They took a claim against Air New Zealand to the Disputes Tribunal for $15,000, which is the most you can seek before that body.
Air New Zealand offered them $2425 and argued the claim was limited by the Montreal Convention, which is an international treaty about passengers and cargo.
But the Disputes Tribunal, last July, found that Air New Zealand made a representation to the Greens which the pair relied on to their detriment.
The tribunal awarded the Greens $15,000.
Air New Zealand then hired Queen's Counsel Nathan Gedye and took the matter to the High Court, with the airline arguing that it was an important test case.
The Greens did not take part in the action.
In his decision released this afternoon, Justice Nation said the tribunal made an error of law and had to recognise the way in which the Montreal Convention limited the airline's liability.
The judge said he sympathised with the Greens but that the law meant they cannot get the remedy they want.
He set aside the tribunal's decision but noted that Air New Zealand had accepted it was liable to the Greens to the extent that the convention allowed for what appeared to be an "unreasonable and distressing delay in recovering a suitcase that had gone astray".
The judge said it would also be appropriate for Air New Zealand to pay interest on that amount.