during WW1, no nation had as many accusations of mis-treatment of POWs as the Canadians did, despite being a minute fraction of the total number.
they pretty much never cooperated with any of the "gentlemen's truces" during the war.
at one point they heard the Germans complaining about a lack of food. so they threw over a couple cans of food. They heard more Germans join that part of the trench asking for more food. so that time the Canadians threw over cans of food...with live grenades in them.
they also had a tendency to make pipe bombs during the war, and one of their favorite tactics was to bury the germans alive in some of the "safe houses" instead of taking them prisoner.
they used similar tactics in WW2. they would "lose" some equipment, boxes of medical goods was a favorite. the germans never had enough stuff so they always scavenged. well the Canadians booby trapped a good number of them. Sometimes just at the site, so when a soldier picked it up, it all went boom. but sometimes they were real sick effs, and booby trapped an individual box, putting a false bottom in so that when the last piece of medical gear in the box was taken out of the box, it exploded. in the hospital. most likely hitting a doctor/nurse type.
beyond the borderline war crimes, they were always known as tough fighters. Kicked our ass the last time we invaded them.
they are nice to civilians, but you don't want to be fighting them.