'You shouldn't miss something as blatant as that': Why ex-All Black is unhappy with Papalii decision

Blues flanker Dalton Papalii was red carded in the 15-3 defeat to the Crusaders early in the second half but the sequence of events after the high shot has left ex-All Black John Kirwan scratching his head.

The Crusaders backs combined brilliantly to put Leicester Fainga'anuku over in the corner for a try before match officials went back to review Papalii's challenge on Richie Mo'unga three phases earlier.

The review showed Mo'unga was hit high but that his pass was dropped by prop Tamaiti Williams before being recovered by Crusaders flanker Tom Christie some 10 metres downfield.

Nic Berry's ruling at the time was 'back off the chest' which was never looked at under the review for the high tackle.

As a result, Papalii was yellow carded, which was later upgraded to a red, and the Crusaders' try unlawfully stood despite a knock-on in the passage, which gave them a 15-3 lead.

"That is a pretty ridiculous decision actually," Kirwan explained of the miss on Sky Sport NZ.

"The yellow card was merited, but there was a knock-on, you had to come back for the knock-on that Tamaiti Williams did.

"That's a critical moment in the game. I think the referees have to go away and look at that. You shouldn't miss something as blatant as that.

"Head high, yeah I get that, but that is a knock-on. You come back for the head high, it is a yellow card.

"But we play on here and that's a try. So that's a really difficult moment at this level."

The 14-man Blues were still able to muster a try-scoring opportunity in the 70th minute when Beauden Barrett produced a piece of magic.

Three kicks in succession had the Blues in position to score when the bounce stumped Barrett just metres from the try line.

The Blues would have just been seven points adrift had the correct ruling been made earlier.

"In saying that, I just think the Crusaders were relentless in the first half," Kirwan said.

"The Blues will go away, and their defence was great, but late in the second half they needed one of those moments that Beauden nearly pulled off."

The visitors fell to fifth on the Super Rugby ladder while the Crusaders moved into third momentarily until the Brumbies play on Sunday afternoon.