JTO, In my view the answer to your question is, "themselves". Given that I am forever railing against self regulation that might be seen as a contradiction and somewhat ironic one at that, but if this scandal has shown us anything it is that you can have all the procedures and regulations in place but if malevolently minded people are bent on circumventing them it requires determined and decently minded ones to resist them, or they will succeed. That is why the guardians of airworthiness and accident investigation must be independent to resist such attempts succeeding yet again.
I pay tribute to all those who have stood firm in the past and to those who stand firm now. Doing the right thing is never easy at the time, but that is the point, for in the fullness of time you will be able to look back and can be at peace with yourself. There must be many who cannot do that now. Given the cost of such moral ambivalence I cannot pity them.