A colleague once mishandles an entrusted item. You can speak respectfully, seek clarification, and set reasonable safeguards before entrusting it again. This is consistent with a clean heart: you have not humiliated the person or plotted revenge.
Conversely, a person may speak politely but secretly manipulate others for gain. Attractive language does not erase deceitful conduct.
Moral character is assessed by honesty, dealings and intentions—not by a confident tone or outward social status alone.