Ndebele wore a secret camera for the Channel 4 Dispatches documentary Undercover Angels, claimed her 'drastic action' resulted in improvements in care at Ealing Hospital in west London.
The 34-year-old, of Greenford, Middlesex, recorded scenes including a patient being force-fed with a syringe and faeces being left on a bathroom floor for three hours.
But she could now be struck off for reporting her concerns to hospital staff and failing to protect the interests and dignity of her patients by filming them without consent.
Ndebele insisted at her Nursing and Midwifery Council hearing last week that she had reported incidents to staff on many occasions, but had been ignored.
She was asked to participate in the film by the Steve Boulton television production company when she was a newly qualified nurse struggling to find work in a hospital.
She denied the charge that she had failed to protect her patients' interests and dignity by filming them, saying: "I think that through the filming we actually promoted and protected the patients' dignity, because by doing so we were able to raise the concerns and issues that these patients were under.
"I think the film did a very good thing, so I don't think I have in any way made a misconduct in this case."
Ndebele has not been able to work as a nurse since the programme was aired in January 2005.
The four-day case has been adjourned until September.