In human subjects research, it's fairly well settled that researchers may not go ahead without the guidance and approval of an IRB, even if their research otherwise lacks ethical infirmities.
What happens in the opposite situation? That is, suppose a researcher gets IRB approval for their project, but later on, ethical issues are found in the research that the IRB missed?
Since researchers are not allowed to trust their own understanding and must seek IRB approval even in the most obvious "there's no way that could be unethical" scenarios, it stands to reason that the opposite is true - that if research has been IRB approved, then researchers may go ahead with a clear conscience even if there could still potentially be ethical issues in the research.
I recognize that there could possibly be civil or criminal liability outside of academia, but I'm not asking about this.
If research turns out to be unethical, but it received IRB approval, who is held responsible? Is it solely the responsibility of the IRB for misguiding researchers, or does the researcher bear some responsibility for not recognizing the ethical infirmity?
Another way of asking this is whether researchers have a duty to police their own IRB, potentially second-guessing their approvals.
To be clear, I'm asking about situations where the average non-expert might be unclear as to whether or not something is ethical. Obviously, if an IRB tells someone, "Yes, it's ok to torture political prisoners as long as you kickback 5% of your grant to us", that's blatantly unethical and no one should accept that, but an IRB saying, "Yes, we reviewed your consent form and we don't think you need to disclose the extremely remote risk of the subject being hyperspace tunneled" might be one where the average person (or even researcher) would just get glazed eyes and defer to the IRB.