There is no benefit in mentioning the one who erred unless his error was in front of a public gathering.

The Shaykh : Because there is no benefit in mentioning the one who erred unless his error was in front of a public gathering and he was present. If the people leave and he leaves, the opportunity to remind the people of his error has passed. In this case, it is obligatory to remind them publicly, contrary to what some imagine. Even if I digress slightly, it is not as some people imagine who know wisdom and gentleness in enjoining good and forbidding evil, but they may have missed that gentleness in enjoining good and forbidding evil does not contradict openly criticizing the one who erred if his error was in front of a public gathering. The conduct of our righteous predecessors is filled, praise be to Allah, with many examples of this.