As of this week I am thinking this spate of announcements may be very similar to the spate of many (i.e., 15+ different firms) that announced 偽造表示 (false labeling scandals), that suddenly happened about 5 years ago, and were announced all in the space of about one month afterwards. Here is a partial list, that I show in my course:
三越伊勢丹ホールディングス － グループの百貨店などにある計１４カ所のレストラン
Not to say that
Basically, Hanshin Hankyu Hotels had a scandal where they lied about items on the menu, when they thought no one could tell the difference. The President took heat also because he said in an interview soon afterward, “we did not really break the law, specifically..” or comments that were interpreted that way. After that, a stream of announcements of other menu or food-related lies by other companies came out. They all seem to have figured that it was a great time to come clean, in the melee when Hanshin had already taken the heat and there was safety in being next and in numbers. My point in my course is that, some of the senior executives in these companies must have known about the falsifications in advance, because you cannot investigate everything in a company anew in only 2-3 weeks, usually. Also, because 10 years ago, such persons were closer to the genba, the front lines, where you tend to hear more gossip. Maybe the board did not know, but some members may have had an inkling and had a duty to tell the board, …but when they first found out, it was “too late” (or they were afraid to speak up) so they went with the flow.
It is hard to say “who knew what when”, and it all depends on the company and the specific case, but corporate culture is everything in situations like this. Do people feel free speaking up about simple lies, large or small?