We often speak the truth sharply, in an in your face manner that stings as the bite of a wasp. The hearer may not long remember the truth that was spoken, but he will remember how the words spoken made him feel.
It were better to have spoken the truth plainly, in an unassuming manner that carried no bite but left a small and persistent itch. As the hearer would scratch that itch from time to time he might just discover for himself the truth of the words spoken.