I think the idea is that you don't incite racial violence because it is all to easy and the next thing you know the streets are full of young men hurling beer bottles and knives along with the insults.
So we have terrorism as a separate category. People are encouraged to dob in a terrorist. And that seems to be working quite well, they do catch quite a few young men before they actually do anything.
From what I saw on the video footage as the car was moving, the man was leaning out of the drivers window waving his arms and yelling. couldn't hear what. he didn't look like he was planning to suicide and ended up being shot in the arm and arrested, we saw a shot of him on the ground, it did not look like fun. I don't think they showed the bits where he was plowing into people, they showed upturned prams and suchlike.