This is one of my favorite documentaries. I don’t think the accident was due to Diane’s drinking, I think what she did was intentional, the drinking was her working up the nerve for her murder-suicide mission.
I think that the convo she had with her brother that morning, there was an argument about their (his & Diane’s mother)…on the trip, the nieces revealed that they had been spending time with Diane’s mother and even possibly she would be at the recital. I think that was the last straw for Diane. She decided that if the family was not going to remain loyal to her, she would punish them all and make sure that her mother NEVER got to see her grandchildren ever again.
And Diane’s entire family, including the parents of the little girls (nieces), all knew EXACTLY why Diane did what she did. They make up excuses for her because of their own guilt in what happened.
So sad all the way around, I feel most sorry for Diane’s little son, I wonder how he is doing.