Having destroyed any evidence in cleaning up the elderly woman she felt unsure what to do. Her word would not count against Mr Tiplady, who had a respected career in the care sector and had won awards. The residents, some blind, some suffering from senile dementia, were unreliable witnesses.
She phoned Action on Elder Abuse, who put her in touch with help. Eventually, she took a swab from another elderly patient's mouth. The specimen was found to contain semen, and sealed Tiplady's fate. Last year he was jailed for four years for indecent assault. The judge condemned "the vilest abuse of trust imaginable".
No one likes to think of incidents like these. But they do happen. Elderly people are as vulnerable to abuse as young children. And because of their disabilities, it can be just as hard for them to be taken seriously. Indeed the biggest problem is inadequate awareness among professionals. That is why we are asking readers to support Action on Elder Abuse as one of three charities benefiting from The Independent's Christmas Appeal. Since its foundation in 1993, the charity has emerged as a vital advocate protecting old people.
Stephanie Coningham was a typical caring professional who thought her aged mother was safe. Ms Coningham, a social worker, thoroughly checked the local authority home into which she placed her mother, Mary Watts, who was 81, suffering from Parkinson's Disease and severe arthritis.
Then, one night, care staff found that a mentally ill old man had climbed into Mrs Watts' bed and was sexually assaulting her. "All the staff did was to take him to his room and report what had happened," said Ms Coningham. "No one took any precautions against it happening again.
"Two days later, during another nightly check, the man was again found in her bed. He had put three cardigans around my mother's face and wrapped one tightly around her neck. He was sexually assaulting her and she was very distressed."
Yet Mrs Watts received no counselling. The man was allowed to stay in the home. His victim had to share the same day room for meals. "My mother had Parkinson's and so had a very passive face," said her daughter. "So the staff seemed to think she was not upset. But she was terribly distressed about being near what she called `that horrible man'. She was a church- goer, a member of a generation that was horrified by any sexual impropriety. I had to explain to them what she needed. I wanted her to have someone to talk to about it, because she was too embarrassed to speak to me, her daughter, about something like this. But nothing was done."
Ms Coningham contacted Action on Elder Abuse, which helped her to complain effectively. "They were superb. They listened brilliantly and put me in touch with a good solicitor." Not wishing to put her mother through a court case, Ms Coningham won a pounds 2,500 settlement, which was spent on extra visits for her mother.
The helpline is not simply for those who spot abuse. It is also for carers under strain.
Like Jane, who, after her parents died, found herself in her mid-twenties solely responsible for the care of her fractious grandmother.
"We loved each other very much but she became very difficult," said Jane. "One day I got so cross when I was driving that I slammed the brakes on and almost shot her through the windscreen. She was very shaken. I became like a horrible bully. I could see people staring at me, wondering why I was shouting at this frail old lady. She was very arthritic. But I would be too rough taking her out of the bath or dressing her. One day, I took her by the shoulders and shook her. I remember that look of bewilderment in her eyes."
Ryan Sampson, of Action on Elder Abuse, says one of the biggest problems is theft. Frequently it is relatives, granted power of attorney, enriching themselves at the elderly person's expense. In other cases it is plain deception.
"In care homes," said Mr Sampson, "they are supposed to receive about pounds 13 a week personal allowance, but many either do not receive it or find there are charges for basics like soaps, which miraculously add up to pounds 13."
Mr Sampson added: "Older people are very vulnerable in lots of ways. They need outsiders who will listen to them and back them up. That's why we are here."
The Action on Elder Abuse helpline (0800 731-4141) is open on weekdays from 10am-4.30pm