Pretty simple reasoning if you think about it. What would you prefer? For instances like this, and there are likely more than this one, to come out into the open and be reported meaning that innocent people are set free, or for these people to be severely punished and therefore provide a strong incentive to not come out and speak the truth? Stop focusing on vengeance and start looking at justice. Not a perfect form of justice, true, but more justice than innocent people sitting in jail and having a black mark on them for the rest of their lives.