Being ethical is the core requirement of an evaluation. If for some reason you cannot be ethical, do not undertake the evaluation, as you will end up doing harm to others, and that is unethical. Although, as a good evaluator, you may have involved all the stakeholders in the planning and conduct of the evaluation, it is possible that sometimes, when findings are not in someone’s interest, a stakeholder will challenge you. It is of the utmost importance that you stand firm on the findings and do not surrender to any pressure from anyone. Surrendering to such pressure is unethical.
Source: Kumar Ranjit (2012), Research methodology: a step-by-step guide for beginners, SAGE Publications Ltd; Third edition.