“Compton allegedly repeated the unpatriotic deed three times in one day. His goal, apparently, was to teach students that the flag is merely a symbolic piece of cloth.”
#1 That is an opinion, not a fact.
#2 If that view were to be presented, it could be accomplished without actually defiling a flag or anything else as blatantly provocative and insulting to dissenting views. As in, he could have just said to the class: “some people disagree with the idea of the flag as sacred, and view the flag only as a symbolic piece of cloth” and then moved on to the next subject at hand.
Of course, I’m assuming the teacher is interesting in actually teaching, and not indoctrinating the students with his personal views. Which is probably a bad bet to make.
Do that and he might get his head cut off, though. It is soooo much safer to offend patriots, though.