The Greens had a disastrous start to their election campaign, losing co-leader Metiria Turei over her admission to historical benefit fraud.
It then began losing votes to a resurgent Labour under new leader Jacinda Ardern. Not only did Ardern claw back Green voters, she brazenly moved into Green territory by putting climate change and cleaner rivers at the heart of Labour's campaign.
Shaw said he had no hard feelings. Labour's commitment to zero carbon emissions by 2050 was a "massive win" for the Greens, which has long had the same target, he said.
"It dramatically increases the chances of getting it done. If they hadn't signed up to that, then I'd have to be negotiating that with them in coalition talks. The fact that we're there already, that's a success for us."
Shaw said that in the final weeks of the campaign, his party has also been battling an issue outside of its control - voter confusion.
"People actually just don't understand MMP. They still operate as if it's a First Past the Post environment, including people who were born after we transitioned to MMP.
"Most of our communication and messaging at the moment is actually around how it works. For example, there's a lot of people who have voted Green the last two or three elections who think they have to vote Labour in order to ensure that Labour gets over the line.
"They don't understand that every vote for the Green Party actually adds to the Labour total."
With survival looking more likely, the Greens have one eye on possible coalition talks after the election. Shaw admits the "ghost of 2005" is still felt within the party.
At that election, Greens were locked out of a Labour Government after NZ First leader Winston Peters refused to work with them. It is not out of the question that the party could find themselves on the outside of a Labour Government again after the election, despite its Memorandum of Understanding.
"A great deal has changed since 2005," Shaw said. "And while history is useful, it doesn't necessarily indicate the future."