we cannot use definition for terrorist here as it does not fulfill the requirement that the action be in the pursuit of a political aim.

That is incredibly wrong. It was an action intended to induce terror, it was entirely aimed at political figures of a specific party, and it was a person who was totally taken in by the rhetoric of the 'other side'. This absolutely fits any definition of terrorism, unless you have an agenda and you're deliberately trying to twist facts.

We can't honestly call them terrorists, and car accidents are overwelmingly still a much bigger problem.

Literally the worst argument I have heard in this entire news cycle. Considering the morons screaming 'false flag', that's really saying something.