Yes, it is indeed sad. As a 60+ person myself, and prone to obesity, I am aware of the risks. However, and this is the take away from this sad occurrence, if you are not accustomed to exercising at your peak aerobic cardiac and pulmonary level, you are well advised to have a full physical examination BEFORE committing to doing any Camino. Hopefully, any lurking problems can be diagnosed and treated before hand. This said, the first day out of St. Jean is a particularly nasty, steep ascent, especially for someone not used to it.
Parenthetically, in 2013 I walked for a few days out of St. Jean with a woman who lived in very flat Florida. She trained for the Pyrenees ascent by going to her local high school athletic field and walked the bleacher, stadium seats repeatedly to build stamina and muscles. It did the trick when the real test came.
As to the unfortunate soul who lost his life while on Camino, I prefer to think of him having started his "eternal Camino." His soul will be out there, mixed with the millions of others who went down the Route Napoleon and the
Camino Frances over the past 1,200 years. He is in good company now.
I will pray for his soul.
Have the Cathedral authorities been notified? In cases like this, I understand that a Pilgrim Mass is typically dedicated to the pilgrim, and a special Compostela is issued to his relatives. I have also heard stories while working in Santiago of surviving spouses, siblings, or children who took up the deceased person's Pilgrim Credencial and continued the pilgrimage on his behalf, all the way to Santiago. That is especially touching.
I hope this helps.