Probably just a take-one-for-the-team Asian business corruption suicide. He was “the most senior executive outside the Shin family that controls the conglomerate” and therefore a suitable sacrifice.
I think it is a fairly common response to any dishonorable situations among old school Koreans. My Korean ex’s brother committed suicide because of losses in his division of a large business. Apparently he thought they could make it up by end of quarter so he delayed reporting it, and it snowballed into a catastrophic loss.