If she was pronounced at a "skilled" nursing facility, the chances it was done by a real doctor are zero, unless one happened to be there at the time.
Huge push to allow RN or EMT pronouncements, has been for years.
Usually, there's nothing that looks as dead as a dead body, but when called to pronounce, you still have to do the work.
She was “pronounced” by a nurse-practitioner. I recently had a tooth extracted. The dentist probed and tested for what seemed like a half hour to make sure it really needed to be extracted and that he had the right tooth. I can tell from the results that he got it right. If this “practitioner” had exerted half as much care with this poor woman (and for her poor family who had to endure news of her death twice, and entertain doubt the second time) this probably would never have happened.