So sorry for the loss of your friend. That is awful.
I have lost friends and buddies from motorcycles, skiing, falling off a pickup, car accidents, falls, ruptured aneurysm during a hockey game, etc. and quite a few cyclists and all were mowed down from behind. So, I am very cautious. Riding only on low traffic roads with a Varia and an Italian bar end mirror cycle. Traffic is low enough that I check every car to make sure it is giving me a little berth.
I took care of a loved one 24/7 in her last 2-3 years of life, she did not even recognize me. If I had the choice and were her, I would not wanted to be alive but that isn't really an option in that state of mind. I figure to start drinking and smoking cigars at 80 and go out that way.