GATINEAU, Que. - An army private says Capt. Robert Semrau saved his life when their outpost came under heavy mortar fire in Afghanistan -- but top brass say the disgraced soldier should be booted from the military.

A military sentencing hearing heard Monday from members of the rank-and-file who served with Semrau, as well as the top commander who was on the ground when the captain shot an unarmed and wounded insurgent after a bloody battle.

Pte. Joseph Villeneuve recounted how Semrau saved his life two years ago as insurgent shells rained down on their forward-operating base.

"We heard 'incoming!' so Capt. Semrau, he said, 'Get behind that truck.' ... We get behind the truck. Sure enough, the mortar hits on the other side of the Ford Ranger, the shrapnel hits the side," Villeneuve said.

"Saved my life right there."

But those heroics don't justify shooting a weaponless enemy fighter who had been nearly cut in half by helicopter fire, the former top Canadian commander in Kandahar testified.

Brig.-Gen. Denis Thompson argued the court has no choice but to kick Semrau out of the Canadian Forces.

"This particular conduct, in these particular circumstances, is such a blow to the credibility to the institution that as a deterrent I don't believe we have any other option than to release him from service," he said.

The general and Villeneuve were two of four witnesses who testified at the sentencing hearing. Semrau was convicted last week of disgraceful conduct in the shooting of a wounded and unarmed insurgent on an Afghan battlefield.

The presiding judge will consider the evidence from the hearing before handing down a sentence in the unprecedented case.

Semrau could get up to five years in prison and dismissal from the military.

Villeneuve had high praise for the captain's actions in the mortar incident. He told the court how Semrau kept a cool head as he tended to several wounded Afghan soldiers, including one whose jugular had been severed by a shrapnel.

"Capt. Semrau was up to his elbows in blood, just helping out," he said.

The 36-year-old Semrau was part of a team of Canadian soldiers assigned to the Afghanistan National Army as mentors.

Semrau had faced criminal charges in the case as well, for second-degree and attempted murder.

The panel found him not guilty of those charges as well as not guilty on a Defence Act charge of negligent performance of a military duty.

Over the four-month trial, which included time in Afghanistan, the court heard from a dozen witnesses.

The testimony included descriptions of what Semrau was alleged to have said in the moments after he fired two rounds in the direction of a badly wounded insurgent.

The man had been strafed by a U.S. helicopter gunship and witnesses described devastating injuries, including a severed leg and a gaping hole in his abdomen.

Court heard that after shooting the man, Semrau told fellow officers he had done it to put him out of his misery.

Thompson said it was never Semrau's call.

"That's not a judgement call to made by a soldier on the ground," he said. "It's to be made by medical staff."