I somehow think that it's the assault on the teacher that would have the lasting impact on the students, not the particular implement that was used. If somebody staved the teacher's head in with a crowbar in front of a class of middle school aged children you think that it would be somehow better than if they saw their teacher got his/her fingers chopped off with a MACHETE?
That when the students got home their parents would say, "Thank God that madman didn't use a MACHETE! That would just be barbaric."