Beurocrat A: "Company X really botched the contract, like to the point of near criminal, definitely civil, negligince, we should probably go after them in court so we don't set a precedent of allowing this sort of thing"
Bureaucrat B: "Don't be unrealistic, company X donated amount Y to <campaign of person who's party currently heads up the executive branch of the level of government in question>, there's no way that would stick."
And then bureaucrats A and B proceed to spend the rest of their day doing things that actually count toward whatever their performance metrics are.
I'm unsure if the drop is due to their scandal and poor management, something specific to Japan/Japanese steel, or if that's a larger issue in the steel market. Nippon also saw a ~55% drop on the same time period.