Present the "brutal truths" to you manager and your manager's manager. This is one sure fire way to be immediately flagged as a person who is not a "cultural fit".
Every ExxonMobil manager that is moving up the rating and ranking and promotion ladder only wants to hear about the things that make them look good. This allows them to claim, "Plausible Deniability" when they see that "the sky is falling."
Plausible deniability is the ability of managers in a formal or informal chain of command, to deny knowledge of or responsibility for any actions committed by members of their organizational hierarchy. They may do so because of a lack or absence of evidence that can confirm their participation, even if they were personally involved in or at least willfully ignorant of the actions.