It was referred to at the time by New Zealand environmental campaigner Pete Bethune as ''a great day for whales, for conservation and for justice''.
A year and a-half later, Japan's notification it intends to resume whaling in the Southern Ocean despite the International Court of Justice decision that ruled it illegal is disappointing, if not entirely unexpected.
Australia filed a case with the court in May 2010, alleging Japan's controversial whaling programme was in breach of obligations under the International Convention for the Regulation of Whaling.
New Zealand filed a separate Declaration of Intervention in 2012, and a three-week hearing was held in the middle of 2013.
At the beginning of last year, the court ruled the whaling programme was ''not for the purposes of scientific research'' and therefore ''not in accordance'' with the convention - to which Japan is a signatory.
The court ordered Japan to cease its operations in the Antarctic immediately.
Japan said it was ''deeply disappointed'' with the ruling, but did cancel the majority of whaling for that season.
However, alongside the celebrations, a note of caution was sounded.
Foreign Affairs Minister Murray McCully warned Japan could still try to sidestep the ruling.
Japan has long argued eating whale meat is an important part of its food culture, and many feared the country would take time to examine the decision, try to find loopholes, or simply put together another programme (which it has done, with a reduced planned minke whale take).
The move is no real surprise therefore, and appears to be another case of commercial whaling under the ''scientific research'' guise.
Mr Key has called it ''in bad faith'' and ''appalling'' and has said he will raise the matter with Japan's Prime Minister, Shinzo Abe, if there is an opportunity at international climate talks in Paris this week.
That is desirable (if unlikely, given the short time leaders have at the conference and the hefty work they have to do on that crucial issue).
Political pressure is clearly required if Japan is willing to defy the court ruling however, and New Zealand and Australia should lead the charge having taken the case to court.
It is to be hoped other countries will also express their condemnation and apply political pressure, too.
For most countries, the scenes of slaughter at sea are outlandish and outdated, and the ''scientific'' claims simply whitewashing.
Many species of whale are endangered as a direct result of human activities.
Although minke whales are not endangered as such, Antarctic ones are protected.
Indeed, the waters around the Antarctic make up the Southern Ocean Whale Sanctuary, one of the two sanctuaries where the International Whaling Commission has banned any commercial whaling.
The next steps are far from straightforward.
Given Japan looks set to flout the court ruling and is clearly prepared to harpoon whales in protected waters, are there any legal means of redress left?
The strong trade and diplomatic ties between New Zealand and Japan, and camaraderie over our shared experience and emergency response in the aftermath of the Christchurch and Tohoku earthquakes, make political interference difficult - but could also make communication possible.
Neither country can desire a repetition of the five-month standoff in 2010 when Mr Bethune was detained by Japanese authorities after boarding one of their whaling ships.
There are a few months left for pressure and persuasion.
(Japan has signalled its intention to resume operations by March next year.)
It would be a sad day indeed if that came to pass.
And sad too if the only remaining line of defence was a small group of activists on the high seas, risking their own safety to try to uphold the ruling of the world's highest court and stop the criminal slaughter of a protected mammal in a protected area.
