TORONTO -- A correctional officer who scrambled to cut a ligature from the neck of a teenaged inmate as she turned dark purple was reprimanded for his efforts, an inquest into her death heard Thursday.

In fact, an emotional Blaine Phibbs testified, a prison manager warned him he could be formally disciplined or even charged criminally if he went into Ashley Smith's cell again under similar circumstances.

"He told me there was no reason to go into the cell. As long as she was breathing, we were not to go into her cell," Phibbs said.

Video of the incident played for the inquest showed Phibbs and other guards entering Smith's segregation cell at the Grand Valley Institution in Kitchener, Ont., about a month before she finally strangled herself.

Phibbs said he had difficulty cutting the ligature from her neck.

"We were having to remove so many ligatures from Ashley's neck, the 911 (emergency) knives were dull," he said.

The apparent life-saving measures only brought rebuke. Management insisted that what had taken place was "borderline excessive use of force."

"I did not agree," he told coroner's counsel, Jocelyn Speyer.

"We thought she was in distress, that's why we entered the cell."

His protests were shut down, he testified, at times seeming to fight back tears.

"You are not a psychologist, you are not a warden. This is my institution, I will run it as I see fit," Phibbs said he was told.

The heart-breaking cycle would be repeated.

Phibbs was slated for further reprimand meetings, including one on the day in October 2007 when Smith, 19, of Moncton, N.B., choked herself to death. Guards, ordered not to intervene, simply watched her die.

On the eve of her death, a distraught Smith awoke after a nightmare that her mother died, Phibbs said. It was one of only two occasions he ever saw the teen cry.

Her mom was the most important person in her life and if she was dead, Smith felt she had no reason to get out of prison, the officer recounted.

Smith, adopted as a five-day-old infant, also mused who her biological mother was and where she fit into her family.

Phibbs said he talked with her about her feelings and problems because she had no one else, even though management had warned him not to.

"We were not psychology," was how he put it.

Smith also said she wanted to go for proper psychiatric assessments but was told hospitals had no space.

"We made a deal that she would try to go back to sleep. She did."

The next morning, Smith showed Phibbs she had a ligature.

She was "begging" him to let her strangle herself, he said.

"Just let me do it. I won't die. I know what I'm doing."

A short while later, Smith was seen on her cell floor, gasping for breath, a ligature around her neck. By the time the officers went in -- Phibbs in the lead -- and started pumping her chest, it was too late to save her.

"I thought she was joking around," he said.

When paramedics finally arrived and cut open her gown, Phibbs said he was angry -- not because he thought she had died -- but because he believed he would be in trouble for being around the exposed female.

Several managers, he said, would act that day as if nothing untoward had happened.

"They all knew."

One reason front-line officers videotaped every key interaction with Smith was to show management -- to no avail -- how difficult it was coping with the disturbed girl, who spent almost three years in segregation cells around the country.

Hours of video show Phibbs and other guards -- barred from entering the cell except in an emergency -- talking to, or negotiating with, the teen through the heavy cell door.

The videos show Phibbs was one of the few people Smith responded to positively. With him, she is mostly calm, if not always co-operative about his requests to hand over ligatures or glass, or uncover her cell camera.

He appears to be kind, gentle, patient, firm. Sometimes she giggles.

"You're going to seriously hurt yourself one day," he says at one point. "You want to hurt yourself?"

"No."

"What happens if we can't get that off you? What if it's too tight?"

On one occasion, Smith became violent, kicking and punching. Guards used a noxious substance, known as OC spray, to subdue her.

"Instead of having staff handle her, it was easier to spray," Phibbs explained.

Phibbs had experienced that spray.

"You spit. You cough. Your nose runs. Your eyes will burn. Your skin will burn. My skin actually blistered," he said in earlier testimony.

Phibbs was charged with criminal negligence causing Smith's death, a charge that was later dropped.

Asked what might prevent another death like Smith's, Phibbs spoke of accountability. Management did not follow policies and procedures and he felt powerless, he said.

"I had no way of reporting that my warden was not reporting incidents. I had no way of reporting they were using the Mental Health Act to get a cavity search done."

"They figured they could keep Ashley alive for the rest of her sentence and she would never come back."

The inquest adjourned until Monday, when Phibbs is expected to face about 10 hours of cross-examination.