Rabada's first offense, of intentionally bumping into Australia captain Steve Smith after dismissing him in the first innings, earned the young quick three demerit points and took him over a disciplinary threshold.
An accumulation of eight points triggers a two-match ban. "It's going to have to stop", he said.
But Usman Khawaja and Mitchell Marsh shared a fighting fifth wicket partnership of 87 and nearly succeeded in taking their team through to the fourth day with at least a glimmer of hope. "I just asked the same question", he added. I just got you out'.
In February a year ago, Rabada was charged for inappropriate and deliberate physical contact with Sri Lanka's Niroshan Dickwella while in July 2017, the pacer was caught using inappropriate language after dismissing England all-rounder Ben Stokes.
Dale Steyn took 86 Tests to reach his South Africa record of five 10-wicket hauls, with Allan Donald only mustering three landmark single-Test returns in 72 matches. De Kock contested his charge of a Level 1 offence but was fined 25% of his match fee.
The hearing was held after play on day three, and match referee Jeff Crowe handed down his verdict on Monday evening (AEDT).
"But I think the game has moved forward since the times I played".
The 22-year-old Rabada was banned for one test in England last year, and also received disciplinary demerit points for over-the-top celebrations in games against Sri Lanka and India. In the wake of this, South Africa captain Faf du Plessis has questioned the International Cricket Council's (ICC) demerit system, saying that it does Test cricket no favors.
Rabada (6/54) ripped through Australia, who started on 180/5 with a 41-run lead.
It's the halfway point of the four-Test series between Australia and South Africa, but there's already been a spate of controversial incidents.
South Africa lost openers Dean Elgar and Aiden Makram early before they were steadied by a 49-run partnership between De Villiers and Hashim Amla.
Pat Cummins (5) and Mitchell Starc (1) followed soon after, Lungi Ngidi (2-24) had Nathan Lyon caught behind and when Josh Hazlewood (17) holed out off Keshav Maharaj (2-90), Australia were 239 all out.
Australia won the first test in Durban by 118 runs.