I spent 20 years in hospital nursing, 10 of it in ICU.
I have been the only human witness to many deaths. Many others died with family or friends present.
The most unusual death I ever witnessed was an atheist. He was in ICU on the ventilator suffering from liver failure.
Liver failure is not a good way to go. He was in a coma, bleeding from the eyes, nose, lungs, in his urine...
He hadn't even blinked voluntarily in several days. When his heart flipped into a lethal rhythm, He sat up, opened his eyes and stared.
It is the one and only time I saw anybody sit up to die. It may have only been an oddity but I still can't explain it and haven't talked to any one that could.