"What happens on the field, happens on the field," Warner said.
"I honestly have no idea what sparked it - I'm still trying to work it out.
"For the first time in my life, I didn't say anything."
In stark contrast to the bizarre sledge he just received, Warner made a classy gesture at the end of Tahir's spell, congratulating the leggie for his handy figures of 2/42 in a brief embrace - but the expression on Tahir's face suggested he was still fired up.
"Immy wears his heart on his sleeve," South African captain Faf du Plessis said.
"He loves doing well. I haven't seen him like that, but it just shows how badly he wanted to win the game tonight.
"He realised that David Warner was playing a great knock and he had to maybe try and get under his skin and the two of them had a few words. That's cricket; that's competitive nature.
"Dave is trying to win a game for his country and so is Imran, so I don't see anything wrong with that."
The situation was flipped on its head when Tahir ran out Warner on 173, but proceeded to congratulate the Australian vice-captain on his knock.
"The great thing was that when Immy was done Dave put a hand over the shoulder and said 'let's have a beer afterwards'. That, for me, is the spirit of the game. Immy is obviously going to have a glass of water, but it's the thought that counts," Du Plessis said.
South Africa has struck gold in selecting Tahir. Having only played 64 matches with the Proteas, the 37-year-old has had a flurry of success, rising to the top of the ICC ODI bowling ranks during last year's World Cup while claiming plenty of key victories for the Proteas.
"He's an absolute gun. Immy is the reason why we are where are as an ODI side," Du Plessis said.
"He's been so consistent over the last few years - he's won me plenty of games."
The weird outburst comes barely a day after the Aussie team was slammed by former Test batsman Kepler Wessels for "mindlessly" sledging South Africa.
"There was a time when Australian teams used sledging cleverly as a strategy," Wessels wrote. "The mindless babble that this group have resorted to is both embarrassing and totally ineffective.
"There is just something very wrong with the fact that players who average 25 are trying to intimidate proven campaigners on the international stage."
Australia now have a huge job to do in recuperating their losses and preparing for next month's looming home Test series against South Africa.