Integrity defines your behavior; it is very obvious in this situation to be a part of behavioral interview questions. This question tests your integrity in its truest way as the recruiter looks interested in knowing two things. First is whether you can distinguish between fair and unfair, and what is your judgment of something unfair. The second is your courage to stand up to something unjust. An excellent answer to this becomes even more critical when applying for a leadership role. The answer here is subjective as different people have different incidents and stories to narrate where they stood up to something unfair. You can describe your story, what went by in that particular scenario, and how you made things right or attempted to make things right. You can also talk about talking to your senior, your HR manager, or even your boss in that situation and how they responded, whether they were supportive or not.