@mary Ann, I don't agree that Gritches wants to shut down any dialogue - in fact I think it clear that he/she (apologies, Gritches, I ought to know, but don't) is trying to engage in the dialogue, just not in agreement with you.
That said, the points you make are just as valid, and it is certainly true that workers (and volunteers, as you rightly point out) are largely untrained and often totally unprepared for the experiences they face. But it doesn't change the fact that they are there, paid or otherwise, because they choose to be, they don't have to be there, doing that.
I am grateful that most of them
do make that choice, and society as a whole needs them to make that choice, but the fact they are largely untrained and unprepared means that when an incident of the kind being discussed here actually does arise, their actions in response often will make the situation worse, because they don't know how to make it better. That escalation will be to the detriment of the autistic child, and the child's reactions will inevitably lead to it being blamed for what has happened, because it's the child's behaviour that gets examined in these situations far more than the adult's.
What we clearly agree on is that there should be far better training, and far better understanding of how autism impacts children (and indeed, everyone). Only by advancing that understanding will incidents like this one stand a better chance of being de-escalated before they get to the point of blame, punishment or restraint. Until that happens, I tend to the view that firstly, autistic children are, first and foremost, children, who largely can't reasonably be held responsible for their actions, but the workers around them are adults, who reasonably can and should be.
Which is not to say we vilify the workers instead of the child - we shouldn't vilify either.