I completely understand why you want to confront him. And yes, short term you will benefit by feeling a bit better, but what long term benefit would it give you balanced against the problems it might cause you?
Look at it this way, he's doing it for one of two reasons. Either he's trying to antagonise your husband because he's piqued about him leaving and is trying to get a reaction which will allow him to pass on a poor reference.
Or the alternative is that he genuinely holds these views. In which case he's a dick. But he doesn't sound like the sort of dick who will have an epiphany because you give him a dressing down. More likely it would just entrench his views that people with disabled family members are entitled, difficult arses who make life tough for poor put upon businessmen like him. And again, could give a poor reference.
Either way, the only benefit will you be feeling better short term. But long term, you won't change this man, you won't change the way he operates his business, he won't stop being a dick.
But you may well harm your husband's career prospects long term in a way which can only be rectified by traumatic, expensive, drawn out legal action which would be hard to win (and may potentially damage his prospects even further). It's just not worth it. Sad but true.