After an intense match, Kohli had accused Smith of looking to the dressing room for help when making DRS decisions. Du Plessis thought both their actions were more serious than his own offence of shining the ball with the aid of an artificial substance three months ago, for which he was charged by the ICC.
In November, during South Africa's tour of Australia, television footage showed du Plessis chewing on a mint and then using saliva to shine the ball during the Hobart Test. Since the pictures were only released in the days after the match, and not in the window during which the umpires could lay charges, the ICC brought a case against du Plessis. He was subsequently found guilty of a level 2 offence, fined 100% of his match fee and had two demerit points added to his record. Du Plessis appealed the decision but lost and has since maintained that his punishment was harsh, especially because other teams, including Australia, admitted to shining the ball same way.
Asked for his reaction on the Kohli-Smith affair, du Plessis said he would have preferred to see the ICC deal his two opposite numbers a stronger hand. "I was [surprised that no one was charged] purely from the reason of what I went through for something I feel was a lot smaller and a lot less... whatever you want to call it. So yes, surprised with that," du Plessis said, after South Africa drew with New Zealand in Dunedin. "It [the reaction from the ICC] was different. I am surprised by the way it happened. Maybe it's just because I speak on from a personal point of view and I felt that I was treated very harsh but when you see something like that you hope that it would be exactly the same."
Du Plessis would not be drawn further into what he thought of either Kohli or Smith's actions though. He had said before this match that he did not expect the ongoing contest against New Zealand to get as tense as clashes against either India or Australia can be, not least because of the differences in the way the series are reported on.
"Us and New Zealand are very similar in the way we play," du Plessis said. "We respect each other on and off the field and we play a similar brand of cricket. We don't see that the way you carry on off the field will have an effect on the outcome. When you play a team like India and Australia that can happen and it's easy to see how that can blow up. For me it has been good to be on the other side for a bit and to see how things unfold. It would have been interesting to see how the Australian media would have reacted to me doing that."