Saikawa insists he would have been perfectly happy to have Ghosn, now 68, continue at the helm of the Renault-Nissan alliance, had it not been for what Saikawa called overwhelming evidence of misconduct.
Ghosn's demise was a "big tragedy for everybody," Saikawa said.
"We spent 20 years creating a good thing through recovery and evolution," Saikawa said of Ghosn's rescue of Nissan from near bankruptcy in 1999 and his eventual creation of a three-way Renault-Nissan-Mitsubishi partnership that became the world's largest auto group in 2017.
"But because of his wrongdoing, it was partly destroyed," Saikawa said.
In an interview with Automotive News, Saikawa said there was no choice but to remove Ghosn when the misdeeds came to light.
Saikawa dismissed talk that Ghosn was targeted by a Japanese coup bent on blocking further integration of Nissan and Renault.
"From the perspective of many in Japan, I was a hero," he said. "I saved Nissan from being merged with Renault. But I wanted him to stay, if it hadn't been for the misconduct."
Prosecutors accused Ghosn and American director Greg Kelly of hiding some $80.5 million in postponed Ghosn compensation from 2010 to 2018. Both men, arrested the same day in Japan, deny wrongdoing. Ghosn faces two additional indictments for breach of trust for allegedly diverting company money for his personal benefit. He denies those charges as well.
At the time, Saikawa said he envisioned a way forward for Renault and Nissan that would have created a permanent partnership without resorting to a full merger or holding company. Ghosn was the only person to broker such a deal, because he wouldn't force a merger, Saikawa said.
Today, Renault, Nissan and Mitsubishi are finally back in the black after years of losses. But ties between the companies, nearly broken after the Ghosn scandal, remain strained. The partners have divided the world into spheres of influence and been largely quiet on joint projects.
Saikawa praised Nissan for finally returning to a growth path.
"I don't know if they have fully recovered from all the days and energy lost from that tragedy," he said. "But in performance, they have recovered to making profit. So they are at the next step."
Saikawa was a loyal lieutenant for much of Ghosn's 19-year tenure, and served as co-CEO with Ghosn over the course of a one-year transition before becoming solo CEO in 2017.
He was forced to resign in September 2019 after it emerged he had improperly benefited from a stock-linked executive incentive program. Saikawa left the automaker in 2020.