Hello, I don’t normally post but I have professional experience supporting parents with ND kids as well as my own personal life experience being ND and growing up in an abusive household.
I think people are reacting in very different ways because it’s the first known incident of violence and it’s not abusive in the stereotypical sense most people usually think of, like closed fist hitting, even if everyone agrees it was wrong. It’s tipping off an object and people may imagine it with different levels of risk or harm for your son. Most parents have lost their tempers at some point and reacted in ways they regret, so it’s also easy to project that onto your H. We don’t know the pattern of past behaviour and none of us know you, so it is also easy for people to fill in the gaps in the narrative given with their own bias or life experiences: you’re a weaker parent and it’s an ND child with no boundaries, dad is ND, dad isn’t, dad is abusive and even worse behind your back, it’s a dad who has made a mistake due to overwhelm, he does everything, no, you do…
I’ve seen all those versions of this sort of story, and bits of them in combination, and in all instances for me this would be a safeguarding referral, because there are warning signs here of abuse. Parents who are abusive usually aren’t abusive all the time, they can have good traits, understandable reasons to react in the wrong ways and may not mean to be abusive, some may need support themselves to better cope.
However, you cannot make your H change or take responsibility if he doesn’t want to and sees no problem with himself or his actions.
You can only control your own reaction and decisions in response to him and his behaviour.
With my own dad, he wasn’t often violent. He tended towards emotional abuse and what is now called coercive control, which made it difficult for my mum to realise he was abusive. It wasn't until things had escalated and she left him when I was an adult, and had to get the police and women aid involved, that she had it explained to her he was abusing us.
He'd have done this with the chair, and would do things like shout for hours at us and mum, including for issues related to my learning disability. It was a high conflict, high stress environment, and I knew they weren't happy together. He'd do things like threaten me with knives for not eating my food. He said that was okay as he wouldn't really cut me and mum was a soft touch... it was abuse. I was scared of him and knew he'd eventually hurt me in some way if I didn't do what he wanted even over unimportant stuff. But it was never his fault and he'd try to turn it into a joke and to get me to say it was okay if he was challenged by another adult. If you only see the one off incident, it's easy to think maybe it's not so bad even if not ideal. His undiagnosed ND issues were a contributing reason but not an excuse for this, and made him vulnerable, so my mum felt sorry for him. He was often under employed and at times easy to take advantage of, while she was a higher earner, better with money, plus doing most child care and all the research and fighting for me with my ND. He’s not an evil man, and he acted from his own trauma, upbring and lack of past support. However, his mix of denial, lack of self awareness, low empathy, stubbornness and black and white thinking, plus unwillingness to compromise, meant he was never going to change and was a danger to us and my mum. She would often say he’s not bad all the time. He could be funny, generous and kind, and if we lived by his rules, appeasing his needs, views and anxieties, things were mostly okay. But that’s no way to live, and it damaged all our mental health. It was harmful for him, as well.
ND men like this potentially aren't unusual and it's possibly part of why ND kids are at much greater risk of abuse. They can have a parent who is undiagnosed with poor coping strategies yet in denial, inflexible and unwilling to change, with poor emotional and impulse control, plus having an ND child is just harder and causes extra stress. - it's not the ND causing the abuse and most ND people aren't abusive, but personality, up bringing, a sense of stigma related to being ND, unhealthy coping strategies and past lack of proper support, can contribute to the risk of parents acting in abusive ways.
Only you can say if your husband sounds more like my dad or more like a normally good parent who might be open to change, but having a bad day, and needing support.
Either way, I think it's good you've documented this and I'd encourage you to document and report any further incidents, because either it could lead to him being forced to take support, or if you separate, result in less time for your children alone with him. But again, you cannot make him change or be a better parent. There are no magic words to fix him, you can provided opportunities but ultimately this is his responsibility to fix.
If he doesn't change, what are you going to do? That you can plan for and control.