Truth and mendacity are two important concerns in Girard's mimetic theory, particularly when it comes to the sacrificial mechanism that in ancient times only worked when the truth of the victim was not known. I have completed a five-part series called "Mimetic Desire and Truth" that explores some of the basic ways that mimetic desire can be constructive and help us discern the truth, not as individuals but as a society but also ways that rivalrous desire obscures the truth. You can get a page with links to each post on the above link or you can go to the first post and continue on from there.
Among other posts is a look at the Salem Witch Trials, a Girardian scenario if there ever was one, through the point of view of a judge who repented of his judgments in Bewitched, Bothered, and Repentant.
The Communal Good Shepherd looks at the Parable of the Good Shepherd and the Lost Sheep. The Good Shepherd in the Desert looks back to the desert journey of the Israelites with the help of a Christological take.
Cast out by the Outcasts looks at the dynamics of the Ten Lepers who were healed by Jesus and what helps and what hinders gratitude.