Ethical consistency or ethical congruence is not about ethics and certainly not about morality. It is about the consistent and fair application of policies to all team members.
When team members believe their are dual standards, unfairness, lack of consistent enforcement or favoritism, morale will be substantially harmed.
Avoid making policy exceptions because of who someone is or because they happen to be a favored team member.
Senior leaders especially must be consistent and great role models for this behavior.
Take special care to ensure you are not creating any appearance of impropriety or favoritism.