As my readers know very well, I rely very heavily on information from ESPN's Jackie MacMullan. She apparently has indicated that, per sources, Kyrie Irving once knowingly failed to sign 100 basketballs destined for charitable organizations - the only one not to do so.
Jackie MacMullan: At the completion of the regular season, #Celtics set up 100 balls for charitable partners. Everyone signed them except Kyrie Irving. Pressed to do it, say sources, he was neither aggressive nor confrontational. He merely said, "No, I'm not interested in that.