After Carlos Ghosn was arrested, jailed and stripped of his titles at Renault-Nissan, two of the alliance’s top executives met in Amsterdam to clear the air.

The dinner, held after a regularly scheduled board meeting, was an opportunity for the Renault and Nissan chiefs to get better acquainted. It was cordial. Then, almost as an aside, the Nissan Motor Co. chief executive, Hiroto Saikawa, dropped a bombshell.

It...