If it hadn't been for the Ontario Nurses Association, troubled nurse Elizabeth Wettlaufer would have been fired years earlier, a public inquiry into long-term care in Ontario has heard.

Brenda Van Quaethem, the top administrator at the Caressant Care nursing home in Woodstock, Ont., where Wettlaufer killed seven patients, testified Thursday that Wettlaufer was friendly but also often late, took long breaks, and made multiple medication errors.

"If you take the union out of the equation, would you have fired [Wettlaufer] earlier?" lawyer Paul Scott, who represents some of the victims' families, asked Van Quaethem.

"Yes," the administrator answered.

Instead, Wettlaufer was given multiple written and verbal warnings to avoid escalating her discipline to suspensions, which would be grieved by the Ontario Nurses Association, the union that represents nurses in the province.

It was cheaper to give Wettlaufer warning after warning than it was to suspend her without pay.

Van Quaethem's testimony came on Day 3 in a four-month public inquiry into long-term care that began this week.

If the grievances were successful, Caressant Care would have been on the hook for back pay and possibly damages, and the money would have come out of a patient care fund.

When Wettlaufer was eventually fired, the union again stepped in and her termination was classified a voluntary resignation. The nurse got a $2,000 settlement and a letter of reference. She went on to kill another patient.

The union challenged Van Quaethem's account, saying it didn't know about some of the problems with Wettlaufer, which included medication errors, shoddy treatment of patients and spats with staff.

But the public inquiry also learned that when the union did grieve several of Wettlaufer's suspensions and her eventual termination, it never reached out to Caressant Care home managers to ask why the nurse was being disciplined.

Van Quaethem was cross-examined by some of the lawyers representing different parties that have standing in the public inquiry proceedings, including lawyers for the victims' families and for the union.

The Long-Term Care Homes Public Inquiry, established on Aug. 1, 2017, after Wettlaufer was sentenced to eight concurrent life terms for killing eight people, is headed by Justice Eileen Gillese. It's set to hear from 17 parties over nine weeks.

The probe will examine the factors that allowed Wettlaufer to inject patients with overdoses of insulin while working at southwestern Ontario nursing homes and private residences for nearly a decade.

Van Quaethem broke down while being questioned by Ontario Nurses Association lawyer Kate Hughes.

The administrator said she didn't remember if Wettlaufer had more complaints against her than other registered nurses. She admitted that, despite being the top official at Caressant Care, she had no training in nursing, human resources or labour resources.

She also didn't have training on reporting problem nurses to the Ontario College of Nurses, which regulates the profession.