A communications "gap" existed between Ontario's nursing watchdog and the care home where Elizabeth Wettlaufer killed several residents, the commissioner of a public inquiry said Wednesday as the two sides discussed why an investigation was never conducted into allegations the nurse was abusive to patients.

Wettlaufer, 51, has confessed to murdering eight patients -- and attempting to kill several more -- over the course of nearly a decade by injecting them with overdoses of insulin at care homes and private residences across the province.

She was disciplined several times by her employers at Caressant Care, in Woodstock, Ont., who ultimately fired her in 2014 after she made multiple errors while administering medication, the inquiry into Wettlaufer's conduct has heard.

Caressant sent the College of Nurses of Ontario a "termination report" on Wettlaufer, outlining some of her transgressions, and saying it had several other documented incidents on file, but the watchdog did not probe deeper into those cases, the inquiry heard.

"There is a gap here, there's no question in my mind," inquiry commissioner Eileen Gillese said Wednesday. "Caressant Care thought that it had prepared a report which should have alerted the college to not only to the concerns it outlined but the concerns and incidents before it."

Evidence presented at the inquiry, however, has indicated that the language used in Caressant's report "would not have triggered" the kind of college investigation the care home expected, Gillese added.

Officials with the College of Nurses have recently had the opportunity to review all the incident reports Caressant Care made about Wettlaufer, College executive director and registrar Anne Coghlan testified Wednesday.

"There are a number of (those) incidents that are of serious concern, as they fall into the category of abuse," Coghlan said.

The college would have investigated the transgressions had it known the full details when the home informed it of Wettlaufer's termination, she added.

In one instance documented by Caressant Care, Wettlaufer allegedly continued to administer a treatment for an impacted bowel despite the patient yelling out in pain, Coghlan.

In another case, Wettlaufer allegedly told a colleague to ignore a patient's request for pain medication, telling her co-worker to wait and see if the patient rang the nurses' bell again.

"A significant expectation of clients and (of) nursing intervention is pain management, and to leave a patient suffering when there is a way to address that is abusive, it's neglect," Coghlan said.

The public inquiry is exploring what failings allowed Wettlaufer's crimes to take place, and what can be done to prevent similar tragedies in the future.

Gillese is expected to release her final recommendations by July 31, 2019.