. 'Normal' children can't be touched, I can't see it being any different in W's case. I suppose it depends on if his meltdown was threatening the other kids in the room?
when I was teaching (in WA and Vic) if a student was at risk of hurting themeselves or others they were removed from the room.
it depends if it was a 'taking their wrist and leading' or 'dragging kicking and screaming' physical removal.
I haven't taught SN but my sister is autistic and would be physically blocked (carer placing themselves between her and others)if having a meltdown. I don't think she was ever physically removed from a class.