A military jury at a court martial in Calgary also acquitted Maj. Darryl Watts of breach of duty.
But the five jurors, all senior officers in the Canadian Forces, convicted him of unlawfully causing bodily harm and negligent performance of military duty.
Watts, who stood at attention while the verdict was being read, shared a long embrace with his wife once the court had adjourned. The courtroom at the Mewata Armoury where the trial was held, was jammed with military personnel.
The maximum sentence for unlawfully causing bodily harm is imprisonment of up to 10 years. Negligent performance of duty can bring dismissal with disgrace from the Canadian Forces.
Cpl. Josh Baker died when a Claymore anti-personnel mine loaded with 700 steel balls peppered the platoon on a practice range near Kandahar city in February 2010.
The prosecution had argued that Watts, who was the platoon commander, turned a blind eye to safety standards and abdicated his duty as a leader when he handed over responsibility to his second-in-command, Warrant Officer Paul Ravensdale, who was an expert on the weapon.
"Every case sets a precedent to some extent and what this case does do ... is say if you have your subordinates run a range, you remain accountable the way they run the range," said military prosecutor Maj. Tony Tamburro.
"In my opinion, if commanders weren't responsible for the way ranges were done, that would cause people not to join the Forces."
Defence lawyer Balfour Der had argued that Watts had no training on the C19, so handed over responsibility for safety to Ravensdale.
The lawyer choked back tears as he spoke to reporters after the decision Tuesday.
"I'm disappointed but I'm just so glad the manslaughter charge and the other two explosive charges are gone," he said.
Der said his client was relieved that the jury's verdict was over.
"But he's deeply disappointed in being convicted of anything. The whole thing's really tough on him and his family. He feels very guilty about the loss of Cpl. Baker, one of his men, and Major Watts is such a good soldier."
Asked why he was so emotional, Der said: "I feel very strongly in the man's innocence, and I feel very badly for him and his family to be put in this position of being found guilty when he doesn't think he did anything wrong."
The day of the accident, the range was divided into four training sections. The first two tests of the anti-personnel mine went off without a hitch. But when the second firing occurred, the ball bearings fired backward, hitting Baker and four others.
Videos show several soldiers, including Watts, standing around watching the test. They were not inside armoured vehicles or standing behind them for cover, as set out in Canadian Forces safety guidelines.
Watts's commanding officer, Maj. Christopher Lunney, pleaded guilty to negligent performance of duty in September and was demoted to captain and given a severe reprimand.
Another court martial is pending against Ravensdale sometime in the new year.
A sentencing hearing headed by Cmdr. Paul Lamont, who is the judge presiding over the court martial, is to begin Jan. 14.