Michael Moore's Betrayal of Bethany Deaton

For Tyler, the news was overwhelming. He has been in therapy to work on what he refers to as control issues. For Bethany's friend, Taryn O'Brien, there is one nagging question about the whole tragic situation that keeps coming back to her. Why couldn't we see the unhealthiness of the situation before she died? What would you say to other parents who are concerned that their child may be involved and dangerous?