I agree with Steve, the Rittenhouse case is so far away from terrorism primarily because of his intentions, that the word just does not fit. Now to your comment:

I agree the left does have a tendency to expand a words usage beyond recognition. I also agree that words shift, and need to shift over time.

In the case of the word terrorism. I have never liked that word much, since it is wielded as if it were objective. but is usually is not. It depends on which side you are on to decide is a person is a terrorist or a freedom fighter.

for example many do not describe Israel's demolition of homes that are involved in rocket launches as terrorist acts. Still no one deny's the owner of the home often did not launch the rocket, but are civilians. Israel is trying to break the political will supporting these actions, by attacking the population at large (as well as the actors when they can).

Others WOULD call this a terrorist act, and would say the Palestinans are simply acting in self defense. Thus I think the word is not an honest one. It tries to put an air of objectivity on what is truly just an opinion about who the "good guys" are.

Maybe a word like aggressor is an honest substitute for Terrorist. (of course most speakers are not striving for honesty.)