You should know a red card when you see one.
Which is hard to explain why Springboks midfield replacement Damian de Allende was given his marching orders in his side's 25-24 defeat to the All Blacks this morning.
De Allende became the ninth Springboks player to be sent off in test rugby when French referee Jerome Garces gave him a red card following a late hit on All Blacks replacement first five-eighth Lima Sopoaga.
The incident occurred in with four minutes remaining, an the All Blacks holding a five point-lead, when Sopoaga missed a dropped kick attempt and was taken out late by de Allende.
De Allende had only been on the field for 14 minutes when he attempted to charge down the kick but failed to pull out, running into Sopoaga.
He certainly could have done a better job withdrawing from the tackle and a penalty decision would have been a fair call. Yellow card at a push. But a red seemed very harsh.
It didn't help that it took an injury break to Boks' skipper Eben Etzebeth for Garces to actually use the stoppage as a chance to go to the TMO and have look back on the possible infringement,
After an initial review Garces wanted a second look.
"What I saw on the big screen...it's late. I just want to know if the elbow or arm touched the neck or the head?" Garces asked TMO Rowan Kitt.
A clear side angle showed de Allende's left forearm hit Sopoaga across the top of his chest before moving up towards his chin.
"For me it's clear. The elbow is late. Deliberate. The elbow touched the head. It's a red card," Garces told Kitt, without any input from the TMO.
The fact the referee is making the call off a big screen and the TMO is pretty much a man with a MySky remote should be worrying for rugby.
It should be the TMO's job to make a clear call since he has the benefit of a TV screen directly in front of him where fractions of a centimetre matter between a head shot or just hitting the chest.
Red cards used to be reserved for malicious behaviour such as a punch, a bite or a kick to the head. But late last year World Rugby changed the laws around high tackles - a zero-tolerance approach to reckless and accidental head contact.
It's the reason Sonny Bill Williams was sent off in second test against the Lions in Wellington after his shoulder connected with Anthony Watson's head in a tackle attempt. yes, Garces was the referee that day as well.
It was more clear cut decision by Garces but one that once again needed countless replays and a big screen.
Under the new law, if a player makes a tackle where they knew there would be risk to an opponent's head, the minimum punishment will be a yellow card. That includes a tackle that starts below the shoulders.
The decision probably didn't cost the Springboks the test. It should have been a penalty and the All Blacks took an eight point lead with three minutes remaining. However it shows that rugby still hasn't got the system right for dealing with incidents like this.