They've..em...sharpened it up since then
To understand this entirely, you need to understand the history between Ireland, New Zealand and Munster. It's mythical. The match afterwards was astonishing.
Understand, at this point (2008) the Ireland national team had been playing the All Blacks for 100 years and never beaten them.
Never.
But one Irish team had. In 1978, The All Blacks toured, and decimated everyone in their path - England, Ireland, Scotland, Wales all put to the sword.
Eighteen matches.
Seventeen wins.
One loss.
The loss was to Munster,a provincial Irish team who are the current URC champions. Back then, an amateur side that wasn't even a club side, turned over the unbeatable, undefeated, Grand Slam winning All Blacks 12-0.
The Blacks didn't even score.
The game is mythical in Irish rugby, a miracle that plays have been written about. Much of monsters romantic aura, which matured in their herculean quest to win the European cup, was born in this match.
Fast forward, 30th anniversary. The all blacks came again, and Munster, denuded of its Irish internationals, face the All Blacks again. That's the video above.
New Zealand won this time.
Just.
A last-minute try by Joe Rokokoko to edge the match 18-16, after Barry Murphy's earlier try for Munster, the only try the All Blacks conceded on the entire tour.
Anyway, THIS is how you do Haka.