Seattle case different. There, the teacher placed self in danger to protect others.
But what george said is very interesting and is what I was hinting...
I certainly have not heard of any descriptions of the dead teacher other than as an innocent victim of a mindless crime. In the case of the Canadian Guard, he was a living part of a national symbol and to some degree represented all Canadians. Moreover his murder was rather clearly a manifest symbol of a continuing threat to all of them, by a growing and organized movement.
The reservist was simply standing near a symbolic bit of statuary and adding to the symbolism by his presence. There's no production going on and really nothing of social value at all is achieved - other than the symbolism. He's not helping anyone (as a teacher would be) and he's really at a level of risk near zero. We can safely assume that a reservist at this post is far, far less likely to be in danger than if he's in his own home.
So the application of a word like "hero" rests entirely on some symbolism. And that's the insanity.