If a vehicle can't react to the emmergency break of the vehicle ahead, it's their fault. Change the kitty for a child and the complaint of the scooter is nonsense.
The reason why the guy behind me survived is because he did veer when I slammed the breaks
It sounds more like instead of learning a lesson about following too closely, he decided to turn the mix of anger or fear onto you. Hopefully, with time removed from the situation, he will realize that he should not follow as closely. And hopefully you won't be too affected by guilt-manipulation. (Obviously, it's a good idea when something behind you cannot slow quickly, to try not to brake too quickly, but in theory, a scooter should be able to stop very quickly.) With hard calls, you only can do your best with the information you had at the time.