He said no one within the commission had directly hired or subsequently managed a family member "and thirdly for the most part, those people worked in different areas".
Stories of nepotism and hiring practices that breached public sector standards were "either largely over-rated or in most cases wrong".
He believed the allegations had unfairly "besmirched" the organisation.
Mr Wintringham's comments come just days after figures released to media revealed about 30 EQC management and field staff had close family relationships with other staff within the organisation.
Those relationships were revealed after management and also field staff applying for jobs for 2012 were asked to fill out a conflict of interest form late last year.
An independent review of the recruitment process for 2012 staff cleared the appointments.
The review was prompted by allegations of nepotism and "jobs for the boys" within the commission's highly paid field staff division.