It came on the same day that Du Plessis and his Australian counterpart Steve Smith met ahead of the second test in Port Elizabeth starting on Friday to quell simmering tensions between the two camps after a controversial opener to the four-game series in Durban.
Warner had complained on Wednesday that De Kock had made "vile and disgusting" comments about his wife Candice. It led to a flashpoint between the pair but Du Plessis said that if it was true, the comments must have been made after extreme provocation.
"If you know Quinton’s character, you know he is a very quiet guy. I struggle to get a word out of him on the field," Du Plessis told reporters.
"I know he’s a very relaxed, laid back guy. The point leading up to that would have been a lot of stuff said to Quinton, a lot of personal stuff. I thought he actually handled himself well in terms of all the stuff that was said to him.
"Eventually he reached a point where he said enough is enough. Any guy in the world would eventually say something back."
Warner was fined 75 percent of his match fee and handed three demerit points over the confrontation in the players’ tunnel that was caught on CCTV cameras at tea on the fourth day, during which the batsman had to be restrained by team mates.
De Kock received a fine of 25 percent of his match fee and had one demerit point added to his record.
Smith said the meeting with Du Plessis was positive and called on the umpires to take a greater role in calming tensions on the pitch.
"It was nice to have a chat and ensure that we're playing within the spirit of the game and that cricket is what is written and talked about after this game," Smith said.
"It's been all about the indiscretions in the last fixture and that’s not what we want for the game. Cricket has got to be the winner.
"If they (the umpires) hear something going on they should go to either Faf or myself and make sure we have our troops in line and playing within the guidelines."
David WarnerFaf du Plessisplayers’ tunnelPort Elizabeth TestQuinton de Kocksouth africa vs australia 2018vile and disgustingwarner de kock
First Published: March 9, 2018, 8:46 AM IST