DH dragged DS off the couch and onto the floor.

[Mincepiesformee]

DS (8) is autistic (on the moderate to severe end) He is mostly a lovely, happy little boy but can pinch, scram and bite when over excited or overwhelmed. DH and I disagree on how best to deal with this. I move away as soon as he begins pinching or I distract him with bubbles or a song.
DS will refuse to move out of the way, says if we do that then it’s teaching DS that he can get away with these behaviours. Earlier DH was gaming when DS began to scram and pinch. I offered DH my seat but he refused to move away and the situation escalated, he ended up physically pushing him away then dragged DS by the arms off the sofa onto the floor. DS then had a huge meltdown which resulted in my sitting with him holding his head to prevent him head banging on the living room floor.
I told DH not to drag him off the sofa and just to move away, that’s what I do and DS loses interest and moves onto something else.
DH said I’m encouraging bad behaviour and not correcting DS.

He dragged a child so they landed on their head, causing such severe distress they tried to harm themselves. That is not “moving” a child, that is a loss of control brought on by his own decision to escalate the situation out of stubbornness. Moving a child would be done in a controlled and safe manner to ensure everyone’s safety. If this is how he treats your son in front of you, can you trust him alone with him? It doesn’t sound like your son would be able to easily tell you if his dad harmed him further.

I hate to be negative but your son may not completely grow out of this, it might be something you always have to manage. My mum supported adults with learning disabilities, including severe autism, until she retired recently and some of them had violent outbursts as adults because they just couldn’t cope with the world. There was no teaching them, just managing their behaviour and de-escalating.

If your DH is unwilling to learn about how best to manage that, and always approaches those moments as a battle of wills, it’s only going to get worse. Dragging an 8 year old around without repercussions is much easier than a grown man and a grown man can do themselves significantly more harm afterwards.

I hope things get better for you all OP, it sounds very hard right now.

He's right. This needs to be stopped ASAP, and obviously your approach isn't working is it..

Both theories of managing behaviour are valid.

Moving away takes away the need to hit out and also shows people will not accept it and ultimately could mean the child losses out as people won't want to interact at that point.
Not moving away also shows that his behaviour does not always get what he wants. By hitting people and them moving away or giving in, teaches rhe brain that this is the easiest and uses less energy to get needs/wants met so will default.

I think might be best to get support for coming up with a plan on managing these types of behaviours, one that comes from a professional model of behaviour support and utilises functional behaviour analysis etc. Something that will work in all setting and one that everyone can buy into.