You know how they say that women have intuition about these things ("God whispers")? That instinct she had to not return his call probably saved her life. That he went to such great lengths to punish her by setting up his suicide scene for maximum impact, to REALLY hurt her is very telling. Of course she's traumatized because that was his intention, his Plan B. I'm telling you, if she'd returned that call, it would have been Plan A: he would have gotten her over there and taken her with him. Her instinct to pull back was on the money. If she were my daughter I'd be angry too but, believe me, in time, you'll both realize how lucky you are that SHE's alive.
God bless his parents, you and your daughter. I'm so sorry this happened and I'll be praying for your peace of mind.