The impressive part is that kind of thing just naturally happens, and the discussion comes around whether it fits the school shooting framing or not.
There are guns everywhere, in every country. In the most peaceful places there will be some portion of cops allowed to wear guns, there will be hunters with permits etc. There will always be a non-zero chance to be shot.
But whether that non-zero chance is 0.00001% or 1% makes a world of difference and will have deep impacts on how we live our life, talk to people, deal with confrontations.
A low enough probability brings radical changes.