If he is seeking justice for someone else.....without positive proof, then perhaps it's not his place to snoop. A quiet way of a little heads up maybe?
Definitions of retribution on the Web:
a justly deserved penalty the act of correcting for your wrongdoing vengeance: the act of taking revenge (harming someone in retaliation for something harmful that they have done) especially in the next life; "Vengeance is mine; I will repay, saith the Lord"--Romans 12:19; "For vengeance I would do nothing. This nation is too great to look for mere revenge"--James Garfield; "he swore vengeance on the man who betrayed him"; "the swiftness of divine retribution" wordnet.princeton.edu/perl/webwn
Repayment, fiscal or moral; often used as a synonym for karma in human affairs. A tendency exists to apply the word specially to the seemingly bitter aspects of karma, as being the so-called punishment for evildoing; and reward is commonly applied to that aspect of karma which brings forth happy, pleasurable, and elevating factors in human life. See also KARMA http://www.theosociety.org/pasadena/etgloss/red-roos.htm
