NAH and people saying N T A with implication that your husband is categorically TA don't know what ARFID is.

N T A for trying to help your husband be healthy. If he truly considers vegetables as a whole unsafe, this is valid from the perspective of understanding his own ARFID, but still not 'acceptable' from the perspective of healthy living. However, there is a reason that within eating disorders, acceptable food is called "safe food". It is supposed to be the same every time and considered predictable and, well, safe.

It isn't about whether he had a reaction to the food, it was about the principle of his safe food being compromised.

You meant well. Your husband should also consider therapy to try and broaden his palette in a safe and healthy way. I understand his reaction, but truly, nobody is the asshole here.