Home nurses aren't 24/7. Even if so, few actually become "friends" and it only a professional relationship. Elderly usually do not want to leave their home. But often it is just too dangerous to not do so = particularly when their spouse dies and that elderly person is alone.
If the staff of assisted living facilities go beyond the basics, they cross a very dangerous line not only legally, but also towards potential abuse and "practicing medicine without a license." In a medical situations they are to call 911. That's what that nurse did. The 911 operator wanted to her specifically do what she - and everyone - there had been instructed to do. She was correct to refuse to do so.
It would be little different than a cop deciding procedure and laws are wrong and go maverick renegade thinking it best.
My grandmother is an elderly housing place. She is almost 90 years old and prefers to live independently. Her own home got to be too much for her, and it was too big, so she chose to move to independent elderly housing. I'm not even sure if they have a nurse on site.
My grandmother is old but she is very independent and can still get around and still has her wits about her. She's really quite amazing.
“The reasonable man adapts himself to the world: the unreasonable one persists to adapt the world to himself.
Therefore all progress depends on the unreasonable man.” ― George Bernard Shaw, Man and Superman