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

The Shaykh : Because there is no benefit in mentioning the one who erred unless his error was in the presence of a gathering of people and he was present. If the people leave and he leaves, the opportunity to remind the people of his error is lost. In this case, it is obligatory to remind them publicly. This is not as some people imagine—though I might digress slightly—not as some people imagine, those 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 the presence of a gathering of people. The conduct of our righteous predecessors is filled—praise be to Allah—with many examples of this.