They won the second test by a solitary point and they drew in Sydney against the Wallabies with arguably their worst performance in a decade.
The only real highlights were the third test destruction of England, the Eden Park annihilation of the Wallabies and a gutsy win against the Boks in Wellington.
If Slade missed the conversion, the All Blacks were going to have played 10 that year, lost two, drawn one and been fairly ordinary and undeserving in two of their seven victories.
Less than a year out from the World Cup they would have been starting to look wobbly, vulnerable even as if they had timed their run badly, hitting reverse as they approached the big event.
If he was successful, though, the All Blacks would win the game 29-28 and show once again they had the most incredible mental fortitude, strength of character and cast iron will to win games they had no business winning.
The truth about that test in Brisbane is that the All Blacks were mostly outplayed by a better Wallabies team.
Australia won the physical battle, played the more creative rugby and yet somehow, the All Blacks managed to cling on to give themselves the faintest chance of salvation.
A Nic White penalty on 76 minutes saw them go 28-22 down, so it really was only the faintest chance. Yet, just as they had done in Dublin the year before, under the most intense pressure, the All Blacks stayed calm, moved the ball, made good decisions and worked Fekitoa over as the hooter went.
It had been an incredibly effective four minutes after 76 minutes of forgettable if bravely resolute rugby.
What was at stake never entered Slade's head - he simply lined things up and slotted the ball down the middle and in doing so, he let the world see that the All Blacks were not in decline, or any kind of lesser version of their former selves.
They remained the toughest side in world rugby and far from giving any competitors hope that night, the All Blacks crushed it.
They reinforced their impregnability. They proved to everyone - including themselves - that they had this indefatigable spirit that manifested itself in an ability to perform almost perfectly under the most intolerable pressure.
They knew that night they were ready for the World Cup - maybe not in the fine detail of their selections and gameplan, but mentally, psychologically, they knew they had all the tools they needed.
For the Wallabies, the blow could hardly have been crueller or the consequences more dramatic.
A victory would have seen them draw the series and maybe gone some way towards drawing a line under the festering scandal involving Kurtley Beale, a member of the Wallabies management team and coach Ewen McKenzie.
Instead, they were left with more heartbreak, more reasons to believe they were as mentally frail as the All Blacks were dominant and that the culture of the Wallabies and the wider Australian rugby landscape was in fact more rotten than it was perceived.
Half an hour after Slade knocked that kick over, McKenzie announced his resignation, Australian Rugby Union chief executive Bill Pulver began a doomed war against the media by blaming them for the demise of the game across the Tasman and the search for a new coach frantically started given the Wallabies were heading to Europe 14 days later.
That one kick changed everything.
