Of those people who intervened in our "Primetime" hidden-camera experiment, many had personal knowledge or understanding of elder abuse or were health-care professionals experienced in working with the elderly.
When Joe Insigna witnessed the caregiver abusing the elderly man, he called 911.
"My brother was in a nursing home," he said. "He was paralyzed. And a few of the nurses were pretty abusive to him. So I know what it's like to be helpless and not be able to defend yourself."
Lorraine Jacobson, walking her dog in the park, persuaded her son, Scott, a lawyer, to stop and talk to the caregiver.
"I've worked with Alzheimer's patients, developmentally disabled patients, but this is not the way to deal with a patient," she said.
Women were just as likely as men to get involved and question the caregiver's abusive treatment of his client.
Adriana Peel, a special education teacher, ran right up to the elderly man to question him about his care.
"Is this the way this man speaks to you all the time?" she asked.
The man in the wheelchair nodded, but the caregiver kept abusing the old man.
"You're like a little girl, that's what you are," the actor posing as the abusive caregiver said.
Peel was furious.
"Listen, I'm in the health field, and the way you're talking to him is abuse," she said.
"Abuse?" said the caregiver. "I think you've been watching too much 'Oprah.'"
With that, the woman pulled out her cell phone and dialed 911.
Patty Leitch, walking in the park with her toddler, Rocky, approached the two men and engaged them in conversation. The caregiver tried to elicit some sympathy, but Leitch didn't have much.
"Imagine a child who never grows up," the caregiver said, sharing his frustration.
"That's your job, dude," Leitch responded. "You chose it. Get out of the profession if you don't like it, man."
After being told that both the abusive caregiver and the elderly man were actors and that the scene had been staged as part of "Primetime's" experiment, Leitch explained why she had gotten involved and recalled the important role an older person played in her life.
"I was very close to my grandmother who was in a home, and we made sure she wasn't treated this way," she said. "I think our elderly need to be much more respected than they are."
Berni Patten, the diminutive 90-year-old actor playing the elderly man, found this to be one of his most satisfying roles.
"I always figured that people would just pass by and do nothing. But more and more, I see people beginning to care about old people. And that makes me feel good," Patten said.