The headline reads "Walkerton man injured using a grenade launcher" but reading the story itself, I'm thinking it was one of those 37mm flare launchers. I checked at INGO, but they don't have any news yet other than links to the AP wire story.
Anyway, apparently the illumination round detonated in the tube and messed the guy up.
Makes a .40 cal Glock kaBOOM! seem a little passé by comparison, though, doesn't it?