Lesson 1 :  If you have witnessed someone cheating or harming another person, and you are sure that s/he has not compensated the victim, you may relate this incident to another person for either of 2 beneficial and constructive purposes.

 

Lesson 2 :  Continued from above - condition A: if what you are saying with all the victim in receiving compensation for their loss. or B. your narrative will prevent others from harm by showing them that dishonest people are held in disdain. It is also possible that the person you speak about will mend their ways by learning that they cannot get away with with such behavior.