NTA at all.

My partner has CPTSD caused by childhood trauma, when he is triggered he enters psychosis and he has done this laugh/cry before in that state, it sounds very similar to what happened to your husband. I have done my best to learn what to do in those situations and you have handled it incredibly well.

It is uncontrollable, they are in another world in that state and even cannot make out other people or anything around them, he did not laugh at the situation he laughed because it's an involuntary reaction and if you haven't seen it yourself it can be hard to believe or understand. It makes me so sad that some people cannot understand or don't try to.

I am so sorry about what you and your husband have been through. All the best for your future, and well done for having his back.