Past year the High Court in Pretoria found that the NPA should not have withdrawn the 783 counts based on the spy tapes' revelation that then head of the Scorpions, Leonard McCarthy and then head of the NPA, Bulelani Ngcuka schemed about the timing of indicting Zuma.
Shortly before the 2009 polls, after Zuma had won the contest for the leadership of the ruling African National Congress, Mpshe, withdrew 783 charges linked to the multi-million rand 1999 arms deal.
He added that, even if the court said Mpshe's decision had been irrational on further, substantive grounds, "then someone has to make a rational decision on our representations".
Zuma wanted the opportunity to make fresh representations before the NPA chose to recharge him.
Both the NPA and Zuma turned to the SCA after the High Court denied them direct access for an appeal.
But last month Zuma and the NPA made an about-turn and conceded that Mpshe's decision not to prosecute Zuma was irrational.
Machirunga said that in the event that the judge rejects the appeal, but the NPA chooses not to continue with prosecution, then in his opinion the only remaining remedy would be a private prosecution. He also conceded that a decision to withdraw charges that was based exclusively on the timing of the indictment was irrational.
Arguments about what was to happen with regard to the legal proceedings against Zuma, dominated the rest of proceedings, before judgment was reserved.