His final act as an All Black had been to kick a conversion with his right foot, probably the only time in his 112-cap career when he put himself before the team.
'It had always been a dream of mine to kick a Test goal right-footed,' Carter said. 'I used both feet when I was kid, but never in a Test. So there it was: 30 seconds to go, outside the seven-point buffer. I thought, "That's the way I want to finish my career". When I got back, the team were ribbing me because they thought I was hot-dogging. I probably could have done it before, but I'd never thought about it.'
Not when the All Blacks were approaching treble figures, not on the many occasions when they could not possibly be reeled in or contained. Carter's sense of duty had always won the day.
And then, with the seconds counting down until he became an ex-international rugby player, he let rip. Carter kicked his final two points with his right peg. The lunatic.
When Australia clawed their way to within four points of New Zealand, it was Carter's drop goal that took the game away from them again - and his long-range penalty that returned the gap to double figures. His kicking took more than nerves of steel; it took a unique ability to separate the act from its consequences.
'I'm doing it for my mates,' Carter said. 'That's the big motivation for kicking - not wanting to let your team-mates down. I never think in individual terms. You can never take credit. The team is always bigger than you. With the penalty, once you commit to it, you tell the ref you are going to take the shot, you get the tee, that's when it just becomes a process. From that moment, no kick is different to the one before.
'From training to the World Cup, my routine is the same. Make sure you stay in the moment - otherwise your mind starts wandering.
'It's a routine set in stone. I remind myself to go back to process, get to the back of my run-up and breathe. Visualise the ball going through - then remember to breathe again.
'I wasn't thinking about where we were in the match. I wasn't really thinking about this being my last game. I had to have my "now focus" rather than my "outcome focus" where all you keep honing in on is the result.
'It was the same with emotions. If I started drifting into, "Oh, this is going to be my last game, this is going to be my last haka..." I'd lose my attention to the job. So all week I was playing mind games, battling to stop myself thinking about the result. I did that at Twickenham, too. I performed in the moment and that was a big part of playing as I did.'
Carter watched his first World Cup at the age of five, at home in Southbridge. He was already a rugby obsessive and the haka left him spellbound.
'It's one of my earliest rugby memories,' he revealed. 'In front of the TV doing the haka with the team, watching the match, then going up and doing it again in front of my mirror.
'I didn't know what I was at, just slapping my thighs and making lots of noise - but then to be able to perform it for real...' He drifts off and it's not just sleep deprivation or the hangover. Carter is now coming to terms with his status as an All Black being mere reminiscence.
At the end of Sunday's final he was searching in the huddles of celebrating players for his team-mate and friend Richie McCaw.
All Blacks coach Steve Hansen named McCaw as the greatest All Black of all time, with Carter a close second. Both were playing their last game, McCaw as captain.
'Richie was the first person I wanted to see,' Carter explained. 'He put his heart and soul into this side, I knew how much it meant to him. I've been fortunate enough to play with him for so many years, we're really good mates and have achieved so much together. It was great to see him smiling.
'We didn't need words then - but just before the presentation we started talking about this amazing feeling we were having, the joy and satisfaction, yet knowing we would never have this emotion ever again. It was a tough one, bittersweet really, and it will probably only begin to sink in over a couple of days.
'That's what I love about rugby. Working alongside your mates, the sacrifice they put in that motivates you to do the same. Never letting anyone down - it's such a powerful bond that you get and to sit in a changing room afterwards when you've all gone to war, look your mate in the eye and be proud. There's no feeling like it.
'Every time you put on that All Black jersey you want to add to what is an amazing legacy - a side that is known all around the world.
'That was my challenge, but I'd like to think I've done that with the career I've had, the performances over 13 years, the trophies, how many Tri-Nations, how many Bledisloe Cups, World Cups. I'd like to think there's a legacy, that I can walk away satisfied with what I achieved.'
Carter has a memorabilia room in his house but is not obsessive about his records. When asked if he knew the precise total of his points record, he was stumped.
'Oh, no idea. Close to 1,600? Am I right? Yes? Sorry, I know Bledisloe Cups, because I've never lost that.'
As a New Zealander, never having lost a series to the enemy is one of his proudest claims.
There were more celebrations planned for last night, and team officials could be heard organising the return of buses at some ungodly hour. Private rooms were booked, with DJs.
Carter thought he could already hear his team-mates singing upstairs. It was actually a 16-year-old's birthday party in the function room next door, but no matter. This was his moment. His perfect ending.
'I was really pleased that I made the decision that this would be my last year with the All Blacks,' he said. 'You've got to draw a line somewhere, stop dragging it out. I never thought my career would be defined by this tournament. I think I've achieved enough in the last decade not to have that.
'Having said it, though, this was the dream finish, a fairytale way to end.
'You know, I have had huge expectations of myself and that can be pretty draining. To be able to achieve those standards is what you live for. Those moments when you can really say, "I reached my goal". And that's the end of the chapter.'
-Daily Mail
