Steve Hansen thinks rugby union should introduce a disciplinary report system like rugby league after Benjamin Fall was sent off 12 minutes into the All Blacks' 26-13 win over France on Saturday.
Full-back Fall was deemed to have unrealistically tackled an airborne Beauden Barrett and the New Zealand fly-half landed on his head, with referee Angus Gardner showing a red card after watching numerous replays.
It followed controversy from the first Test, when Paul Gabrillagues was sent to the sin bin for a high tackle and two All Blacks players were not punished when similar infractions left Remy Grosso with a fractured skull.
Hansen acknowledged the rules were followed and the right decision was reached in Wellington, but he suggested dismissals might be reduced if referees could decide whether an incident needs further investigation by a disciplinary panel, like in the other code.
"It's disappointing they lost a player. I know it's tough and they have to look after players but somehow I think that we need to look at something where that can go on report," he said.
"It is a challenge and he got it wrong. The referee had to red card because that is what the rules say.
"Personally, I would like a card that is not out and out deliberate foul play – to be yellow on report for red and allow people to stay on the park.
"The red card always has an effect and it is always a shame when someone is red carded, particularly for an offence that is not really intentional."
Hansen believes the All Blacks could have performed better with their numerical advantage and put it down to a mentality issue.
"We didn't manage the game well from [the red card]," he added.
"In sport one of the hardest things to do is to back up a dominant scoreline with another dominant performance so mentally our preparation may not have been as good as we would have liked it to."
The third Test is in Dunedin on June 23.