If the case is as you stated then fair enough (although simply putting him against the wall and summarily executing him would have been more effective) but I would hate to see the situation arise where we regarded killing a soldier in combat as “murder”, that would be a seriously dangerous two edged sword that would be sure to come back with a vengeance.
The man he murdered was a medic.
And Omar was not in uniform. He wasn't in uniform because Omar was not a soldier. He was also not a citizen of Afghanistan and was not a member of a military force established by and reponsible to a representative government, nor was he a member of a militia established according to the laws of a representative government. He wasn't even a member of a police force.
Instead he was a member of a family of outlaws whose patriarch defrauded Canadian taxpayers in taking money intended for humanitarian aid via CIDA to establish a terrorist recruitment center under the guise of caring for "orphans." Orphans he no doubt was literally raising up for the purposes of exploiting them not only for the cash of well-meaning westerners but for forced recruitment.
His family was involved in a number of terrorist attacks, on on an embassy in Pakistan, also a country in which they had no business. NOt to mention they lived in the same compound as bin Laden for a while, and he was certainly an outlaw with no authority as his own country had stripped him of citizenship. His dear sister was cought brining more bin Laden materials into Canada after 9/11. They are of Egyptian extraction and reside in Canada- neither nation granted them the authority to wage war, or to kill, therefore when they kill they commit "murder."
Strictly from a moral perspective it is "murder" to kill anyone when you have no legal authority to do so. Such "moral authority" is restricted to government, and no government here, in Canada or in Afghanistan had authorized him to kill or deputized him to enforce their laws. Had he and his family been innocent they would have at least had the moral authority to defend themselves after being fired upon but this is not the case [they most likely fired first]. Of course, had they been innocent they wouldn't have had special forces soldiers on their tail, and wouldn't have prepared an ambush for them by letting a 15 year old play with a live hand grenade.