A former New Zealand captain, who played at the highest level for seven years, Crowe's thoughts on the series provide context for one of the most spiteful contests in recent times.
"Never in my 14 years of refereeing have I seen such animosity between two teams that was
mainly a result of the debacle in the previous Test in Durban," Crowe wrote in his decision.
"This I have no doubt is a contributing factor to the events that occurred under this COC [code of conduct] charge."
Crowe presided over the first two Tests, which were marred by a stairwell stoush between Warner and Quinton de Kock, Australia's poor on-field behaviour and Rabada's run-in with Smith.
The Rabada-Smith incident was a major talking point in the lead-up to the controversial Newlands Test. The Proteas successfully appealed against Crowe's two-match ban, which would have ended the star quick's series.
"It is my view, this was another send-off as we have seen before and later in this Test, the
bowler getting right into the batsman space [sic] with some loud aggressive shouting – this
time Rabada got too close and created the contact," Crowe wrote.
"The dipping of the shoulder raises series questions of intent. That he [Rabada] said to the umpire there was no contact and later expressed that he did not feel it in any way, also raises questions."
Heron, however, found Rabada to be a "frank, unassuming and honest witness" and accepted his claim that he was unaware he had made contact with Smith.
Heron also disputed the umpires' submission that because contact was "avoidable" then it had to be "inappropriate and deliberate".
"He [Rabada] was clear and consistent that contact was not intended," Heron ruled. "Given the burden and standard, I would have to disbelieve that evidence for me to be comfortably satisfied contact was deliberate."
The umpires' description of the force of contact as "slight" was taken into consideration by Heron, as was Rabada's contention that Smith had exaggerated the degree of contact.