This pattern sometimes happens in other businesses: Banks with a culture of yelling at the compliance department. "Independent" Auditors getting pressured to sign off on the books of a company, etc. The pushback is not always entirely unjustified — I've been annoyed myself at how much easier a legal department finds it to say "no" than "yes" — but it's often a warning sign.
Let's just say that it is a strong tell that one's ethics may not be defensible if your ethics watchdog is threatening to resign.
Consider for instance the exit of Walter Shaub from the Trump Administration.