Obviously, the requirement that one be certain of the accuracy of his information applies to all situations where loshon hora or rechilus is to be spoken for a constructive purpose. There is, however, an aspect of this requirement that does not apply in all cases.
We have seen (Days 52-54) that the Torah requires us to judge our fellow Jew favorably and refrain from concluding that he has sinned when an alternative way of explaining his behavior can be found. As noted, even when it is clear that the person has sinned, one must consider the possibility that this may have been the result of ignorance or unusual circumstances.
While the Torah does insist that we give people the benefit of the doubt, this should not be done at the expense of others. Consequently, if one has witnessed one person harming or attempting to harm another, the need for accuracy does not require an attempt at justifying the perpetrator’s motives. Even if the act is out of character it must be rectified, and one may, therefore, inform the appropriate parties.