Domingo was on Saturday named new head coach after the surprising resignation of Kirsten on Friday.
At the time of Kirsten's resignation, CSA's president Chris Nenzani said the governing body would put together a committee this week to decide who will be the new national coach.
However, a day later Domingo was named as the first person of colour to lead the Proteas.
Nenzani denied they rushed the decision.
"The decision was anything but panicky," he told the Beeld website.
"When Gary was appointed in 2011, CSA made it clear that the focus will be on stability. Therefore, we wanted to pick a successor as soon as possible."
Nenzani did, however, admit that CSA's board, who had to approve Domingo's appointment, pondered long and hard about the decision.
He also admitted that Domingo is yet to sign a contract.
"The details regarding his (Domingo's) contract will be discussed within the next week, but at this stage we are keen to keep him until at least after the World Cup in 2015."
Domingo will take over the reins after the Proteas’ campaign at the ICC Champions Trophy tournament in England and Wales next month. He already has responsibility for coaching South Africa's T20 international squad.
At 38, Domingo is one of the youngest persons to become head coach of the
Proteas but he has already built up an impressive CV of experience.
As franchise coach he led the Warriors to the domestic limited overs double and
it was during his franchise coaching career that he employed Kirsten as a
batting consultant.