In September, the Court Martial Appeal Court of Canada found Darryl Watts of Calgary not guilty of negligent performance of duty.
It ordered a new trial on a conviction of unlawfully causing bodily harm and a second count of negligent performance of duty.
An official with military prosecutions said Tuesday the military will not appeal to the Supreme Court of Canada.
But Maj. Anne Litowski, the Director of Military Prosecutions 3, said no decision has been made yet on whether to go ahead with a new trial.
"No decision taken yet regarding a new trial," Litowski wrote in an email to The Canadian Press. "Still looking at the file."
She did not say when a decision would be made.
Watts, who held the rank of captain at the time and was later promoted to major, was placed in charge of the training range in February 2010. He was found guilty of the three charges in December 2012, demoted two ranks to lieutenant and given a severe reprimand.
Cpl. Josh Baker, 24, was killed when a C-19 Claymore anti-personnel mine loaded with 700 steel balls misfired and peppered his platoon on the practice range. Four other soldiers were seriously hurt when they were hit by the blast.
The first two tests of the anti-personnel mine had gone off without a hitch that day. But during the next one, the ball bearings fired backward and hit Baker and the others.
Video played at trial showed several soldiers, including Watts, standing around and watching the test. They were not inside armoured vehicles or standing behind them for cover, as set out in military safety regulations.
The Appeal Court found that the military judge who heard Watts's case erred in his instruction to the jury.
"In my respectful view, based on the manner these charges are framed and the definition of military duty, the military judge incorrectly identified the military duty that needed to be proved beyond a reasonable doubt,'' wrote Justice Elizabeth Bennett.
"In my respectful view, this instruction created a fatal error to the charge to the panel on all three counts.''
Two other soldiers were also convicted for their roles that day.
Watts's commanding officer, Maj. Christopher Lunney, pleaded guilty Sept. 13, 2012, to negligent performance of duty for failing to ensure Watts was properly qualified on the C-19. He said he had assumed that to be the case because of Watts's rank. Lunney was demoted one rank to captain from major and received a severe reprimand.
Warrant Officer Paul Ravensdale, who was running the exercise that day, was found guilty of breach of duty causing death, breach of duty causing bodily harm, unlawfully causing bodily harm and negligent performance of military duty.
He was acquitted of manslaughter. The now-retired soldier was given a six-month suspended sentence. He also received a fine and was demoted one rank to sergeant.
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