Does that mean go easy on everyone so that when it occurs to you it will slide also? Absolutely not. What I think it does mean though is let the data speak for itself and be sure to mete out "justice" equally to all people. Some people you work with, you just won't like at all. As a leader I try to use this as an exercise in objectivity and pull my emotions and feelings out of the situation and let the problem and the more specifically the data discovered in the problem speak for itself.
I had sadly experienced this, too often, to occur where the well liked or necessary people get tons of slack and the people with less than popular personalities get none at all. So how to stay above board in both action and in judgement?
Gandhi answers it best with one of his better known quotes:
“Be the change you want to see in the world.”
Behave in judgment towards others how you would want yourself or your team to be treated and be sure to hold your team to the same standards you want to hold others.