Well, my oldest friend and I met the first day of high school and we still recall the reason. The fella sitting between us smelled like a three-day-old diaper and we could not keep from cracking up throughout algebra class.
So, a good casuist would probe your conscience in the confessional to make sure you were not - in your hypothetical example - mistaking an "environmental incident" ( air pollution due to BO ), something any reasonable soul would find immediately offensive, with a premeditated act to deliberately ruin ol' Stinky's social status ( which, most likely, he'd already done to himself without a word from anyone - especially anyone unfortunate enough to have been downwind ).
As for "joe blow", he's a complete twit. In my old parish we had a nickname for guys like him - "target practice". The only responsible way to deal with jerks like that is to learn martial arts and clean his clock. Half the time, it's exactly what bullies need to teach them what horse's patoots they are and they end up being friends with the guy that stood up to them.