My daughter works in a nursing home. She works in (what's called) assisted living and the Alzheimer's units. She is a 100% whistle blower. She had ZERO tolerance for neglect. She's not observed any outright abuse, per se~, but there are enough slackers that don't deliver the care that they're hired for. Meanwhile, she ..like the few rare people you have the great fortune of hiring from time to time, is carrying the load for those who do not. She has a relationship with each resident that she cares for.
In counter balance, and not to discount anything about this particular situation, dementia and Alzheimer stricken residents aren't always rational. Although not frequently, my daughter is temporarily reassigned when the patient is convince that something has occurred can't be returned to stable. For those who really care for the residents, this is par for the course and the documentation and investigation is routine and the records reflect the earnest effort to factor the wild card of the resident in a "one has to beyond reasonably conclude" light.
This is going to be a very difficult situation to contain and control. Our elderly can be quite challenging to care for. Most are public funded and staffing is typically at a minimum and work load is incredible. The odds of finding enough people who value people's humanity and dignity ..often at the sacrifice of their own, is unlikely.