It sounds like Gene died because of dementia.
His wife's body was on the floor and he was too far down the cognitive slope to call for help. That probably means he was too diminished to take medications by himself, too. That probably led to him dying a week later from heart issues.
Their deaths were a bad scene. It's not how anybody wants to spend their last few days.
But, putting myself in Gene's shoes, I might not have wanted to survive this incident if I had the choice. Severe Alzheimers is bad scene that never ends. He was 95yo. His longtime wife & caregiver had just died.