Do you as a leader treat some Soldiers better than others?

As a leader (NCO's mainly), do you find that you treat Soldiers differently when it comes to minor indiscretions? For example, you have a Soldier (E4 and below) that is a 'hard charger', always mentoring the Soldiers junior to them, excels at their job etc. Say one day that Soldier is late to formation (first offense with no other prior mishaps). You pull the Soldier aside and counsel them on paper. But before the counseling session is complete, you inform the Soldier that if no other instances of negative performance occurs within a set period of time, you will destroy that counseling. Sort of like probation. But if a Soldier that was frequently late you decline to mention this when they are negatively counseled. Has anyone done this and if not, do you consider it un-professional conduct of an NCO?