Dinky... Agreed. Absolutely.
My comment wasn't intended to be a sweeping generalisation and I'm sorry if it comes across that way. I have in mind specific experiences, that is my personal frame of reference and obviously, other people have their own.
Perhaps 'inflicted' isn't the right word; it seems to be emotive. I don't know a better word that means what I think. I don't mean it harshly.
I don't know about your daughter's SN but I know about my friend's DD's SN. She can 'flip out' (friend's term) very quickly, anywhere at any time and has no concept of danger, traffic, etc. She needs watching constantly as she's adept at playing quietly one minute and disappearing like a flash of light the next. Obviously, I can talk to my friend about what she (my friend) needs me to do when I'm with her, how I can help, etc. and I do. I would bodily pick up my friend's child if necessary and move her from danger. I know that when my friend's DD is having an episode, sometimes nothing works but to completely pin her down to prevent her hurting herself and other children around her.
I know there's a whole spectrum of SN behaviours and I don't pretend to understand them. I know of what I'm exposed to and believe me, I'm sympathetic. I would do anything to help my friend.
I suppose the point that I'm making is that, to me, a tantruming, shouting, hitting child is potentially a danger to others and yes, some element of explanation to the non-SN child can be given but what do you do when that child is too young to grasp what you're saying? All they see is a child that is out-of-control and could hurt them, they're looking to you, the parent, for assurance that all is well - and then maybe they DO get an unmeant wallop from the out-of-control child. It takes both attending parents to take care of the children - BOTH children. It takes a 'joint approach', in my opinion, not an expectation that non-SN parent/child WILL understand and know exactly what should be done. For clarification, that is what I meant about consideration.
In answer to your question, Dinky, about whether your DD should be segregated. I would say, no, of course not, but then again, I don't believe that you'd stand by and let your child distress or injure another.