"The accumulation of defects in the informed-consent process pointed to a pattern of sub-optimal provision of information."
Mr Hill found the surgeon breached the code of patients' rights and recommended he apologise to the patient.
The commissioner said the woman approached the surgeon because of her prematurely aged facial appearance.
The surgeon told her the MACS-type face-lift - minimal access cranial suspension-plasty - would achieve a fresher, more youthful appearance.
The surgeon made no clinical record of the initial consultation, but in a letter to Mrs A, he acknowledged her wish to "achieve a refreshed appearance with more open eyes and fewer lines around the mouth".
"I believe this surgery will achieve your goals. Once fully healed and recovered some patients opt to have further enhancements made ... most however feel it unnecessary. I believe you are a good candidate for the facial rejuvenation surgery discussed."
At first happy with the September 2008 operation, Mrs A was, by the following January, concerned. She emailed the clinic: "My cheek muscles are firm and the shape of my lower face is good, however, as the softening has progressed the skin below my eyes has become soft and puffy and the surface skin layer on my cheek bones has sagged resulting in the naso-labial folds and folds at the corners of my mouth being more defined than they have been."
By September 2009, she considered there had been minimal improvement in her appearance, apart from her upper eyelids. Other parts of her face were worse than before the operation.
The surgeon disagreed that she looked worse and that her cheeks "failed to meet our expectations ... the result was looking good initially and then for no apparent reason some months post-operatively deteriorated".
Mr Hill said the woman felt "inadequate, humiliated and insignificant" at this consultation.
Expert adviser Dr David Glasson, a plastic surgeon, told the commissioner patients' expectations of surgery were often very high, because of what they were told by the media, the medical industry and, to some extent, medical practitioners.
"Surgeons must provide a balance where they can put the complications in perspective, but not encourage unrealistic expectations."