Hindle also dismissed a second charge that the dentist failed to triage patients and did not use proper safety protocols to reduce transmission risk.
The dentist operated on three patients in early May 2020, when New Zealand was at alert level 3 and only urgent and emergency dental procedures were allowed to go ahead.
All three patients had extractions and dental implants placed. Two of them were elderly and one was a cancer survivor who was "in pain and could not eat", the dentist said in his testimony.
He told the tribunal he tried his best to comply with the guidelines, but agreed his records showed no evidence of it.
Lawyers on both sides gave closing statements on Wednesday, the third and final day of the disciplinary hearing.
The Dental Council's Professional Conduct Committee questioned the dentist's credibility, comparing the sparse clinical notes taken at the time of treatment with the extensive descriptions the dentist gave more than a year later.
The council's lawyer, Dr Jonathan Coates, said the health system relies on health practitioners taking contemporaneous notes that reflect patients' true clinical presentation at the time.
"The health system will break down otherwise."
He also challenged the accuracy of the dentist's "extraordinary" recollection of events 15 to 16 months after the treatments. The practice had a large number of patients and was very busy after lockdown, he said.
The dentist was not entitled to place implants at alert level 3, he said, a procedure the accused agreed did not by itself fit the urgent or emergency threshold, even though the extractions did.
Defence lawyer Harry Waalkens QC in turn said the decision to charge the dentist was "heavy-handed and unnecessary".
The Dental Council's charges were based on a narrow - not meaningful - interpretation of the Covid-19 guidelines, the first point of which was duty of care to patients, he said.
Waalkens stressed the dentist saw only four patients over a seven-week lockdown, which could not be seen as a flagrant disregard of the rules. The Dental Council agreed the fourth patient fit the urgent/emergency care criteria.
Both parties did not dispute the level of care the patients received.
"It's telling he has the support of patients who are the subjects in the charge," Waalkens said.
Poor record-keeping did not warrant disciplinary action, which would leave a black mark on the practitioner for the rest of his career, he said.
The tribunal will decide on the penalty at its next sitting.