Very interesting thread.
Firstly, I am only just becoming aware of the NT vs ND thing and it actually confuses me a little bit. Because I thought the current thinking was we are all on a spectrum - where do you draw the line between someone being NT and someone being ND? I thought the current research has us all on a bell graph with aspergers at one end and autism at the other and most people inbetween - so we are all on the same neural line, just some people are more apsergic and others more autistic.
Secondly, I know many people who are probably considered NT who have taken online autism tests (I know, not how it is diagnosed) because they are curious as to why they don't seem to get the social norms in society. I think the whole dinner party thing just highlights that. Some people would ask and not see/care why they are being rude without being ND and others would never dream of asking because it would just be too much trouble for the host and they would understand how unfair that would be for them. Some people would not be worried that the host might be put on the spot and want to accomodate them, despite it being a total nightmare for them in the kitchen, whilst others wouldn't dream of doing that to their host.
Thirdly, logic and honesty do not go hand in hand. It is not logical to tell someone their hair looks shit after a hair cut, though overall it might be honest. If you did this, you would upset them. It is much more logical to find something nice to say about the colour or maybe how it's a nice length, so that you are making them happy.
Finally, you might think you are being honest when in fact you are simply stating your opinion about something, which is not always the truth. That is why people debate all sorts of things. Just because you believe it is true, it does not make it fact. So, because you believe it is always better to be honest, it isn't fact...if you tell the woman her haircut is shit, another person might believe it looks really funky and love it. You are simply going to upset her because you have stated an opinion as fact, which is incorrect and illogical. Also, if you rock up to a dinner party and say you don't like any of the food or have sensory issues, this again might not be fact but opinion. I would say 'how do you know if you haven't tried it yet?' Logic would say you can't say you don't like something before you have even tried it. It is just your opinion that you don't like it, not fact.
Therefore, to say you are honest isn't necessarily logical or factual. Honesty is about opinion more than it is about fact and logic. You are therefore in the same territory as the host who says 'ok, I'll make you something else' through gritted teeth. Neither of you are dealing with facts. And that's because we are all human and we deal with opinions based on our neurology and experience.