'It's madness. It's undefendable' - Ireland prop's yellow infuriates NZ

A yellow card for Ireland loosehead Andrew Porter for head-high collision with New Zealand's Brodie Retallick has gone down like a fart in an elevator on social media.

Porter's head struck Retallick in the 53rd minute, a collision that the 6'7 second row removed from the field for a HIA, which he ultimately failed.

Experienced matchday referee Wayne Barnes referred it to the TMO and after replays were shown on the big screen and broadcast around the world, many were expecting a red card to be brandished.

However, Barnes explained that as Porter absorbed the hit as a passive tackler, it was adjudged to only have met the yellow card threshold, having been mitigated down from a red.

Despite, the tackle being passive, Retallick's HIA was very real and he didn't return to the field.

What made the decision more egregious for most fans was that Angus Ta'avao was red-carded for a head collision with Ireland centre Garry Ringrose just a week earlier in the second Test.

Many were left scratching their heads at the call.

Former second row Jim Hamilton wrote: "Brodie Retallick looks like he “absorbed” that tackle by breaking his eyes socket."

"A huge number of posters from the NH last week suggested that NZ and the SH nations haven't adjusted to the high tackle laws due to lenient punishments in Super Rugby," wrote RugbyPass journalist Tom Vinicombe. "Andrew Porter just getting a yellow there has raised many questions about NH law interpretations."

Newcastle Falcons media manager Mark Smith wrote: "How was Porter only a yellow but Sean Robinson at Northampton gets red and a 3-week ban? This whole ‘mitigation’ lottery is infuriating. Seems to vary wildly from week to week, ref to ref."

Rugby Report Card posted: "They are taking the piss. How is that a yellow bug last week is a red. What’s doing? We have thrown the baby out with bath water and we have thrown out consistency. It’s madness. It’s undefendable at this point"

"I'm an Irish fan, but think Porter is incredibly fortunate there," wrote EK Rugby Analysis on Twitter. "Not a fan of medium force mitigation"

"Different week. Different interpretation of the rules. Would have been a red card last week," wrote one fan.

It's a debate that will roll on.