We have seen that with regard to loshon hora, one may not speak negatively about someone for a constructive purpose without first discussing the matter with that person. An exception to this rule is a case where speaking to the person could prevent the desired result from being achieved (See Days 45, 72).
With regard to rechilus, the exception may be more common than the rule. When an individual has already harmed someone or is about to harm someone, one should not enter into a discussion with him concerning the matter if this could make it more difficult for the victim to protect himself or attain restitution.
In other situations of rechilus, tochachah (rebuke) toward the perpetrator is a prerequisite for relating rechilus for a constructive purpose. A discussion with the person could preclude the need to speak rechilus concerning him, and dispel suspicions regarding the speaker’s true intentions (Rebuke is further discussed in Days 152-153).