Rchilut = Reporting to someone what others have done or spoken against them.
Lesson 1 If John telling you in the presence of a group
that someone spoke or acted against you, you are still not allowed to
believe it. If no practical/constructive (i.e. preventing yourself from
harm) benefits can be gained by knowing the information, you must
ignore what was said.
Lesson 2 You are not allowed to believe rchilut, even if
it was related to you in the presence of the person who supposedly
spoke against you and s/he remains silent. The silence can be ascribed
to factors other than guilt, i.e. desire to avoid dispute.