The former chair of Mid Staffordshire NHS Trust has criticised a report which led to the Stafford Hospital inquiry.
Toni Brisby told the public inquiry by videolink that she thought it contained "relatively shaky evidence".
In a statement, the hospital's former chief executive Martin Yeates said he had lost his family, career and health.
The Healthcare Commission (HCC) found "appalling standards" of care on the wards and a higher than expected number of deaths between 2005 and 2008.
It was the first time Ms Brisby has spoken publicly since her resignation.
She said: "I apologise absolutely unreservedly to anyone who's received bad practice. It's not acceptable."
"But I equally think it's not acceptable to vilify a hospital, the way Stafford Hospital is vilified, on the basis of relatively shaky evidence from the Healthcare Commission."
Ms Brisby addressed the public inquiry by a videolink after a medical assessment said she was unable to attend.
Mr Yeates was allowed to give his evidence via a statement for health reasons.
In the 50-page document, he described the start of the HCC investigation as "the worst week of my professional life" and said he had comtemplated suicide on several occasions.
"The combination of the media, politicians and local pressure groups can make your life hell, a genuine living nightmare," the statement said.
'Poor history'
Mr Yeates also criticised the HCC, describing it as an organisation which "operated on the basis of developing hypothesis, and then finding the evidence to support it".
"I genuinely believe that I and the team at the trust were attempting to improve the services to our patients and local people at a difficult time with many constraints in an organisation that had a long and poor history," Mr Yeates said.
Mr Yeates said he was about to resign when he was asked to step down.
Ms Brisby told the inquiry she would not have left the trust unless told to do so by the head of Monitor, the independent regulator of NHS foundation trusts.
She said she "probably would have wanted to stick with it, and carry on the work".
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