Hmmmm... Personally I think this takes dissecting JC's humour a bit too much and giving him far too much credit, IMO.
"I would say that Carr changes his act for TV not because he wants the work, or is banned from saying certain things, but rather because he has acknowledged that the wider audence has not chosen to be 'in' on it and participate in the social experiement that is his act. It is a very strong act. Not everyone wants to hear it (as demonstrated by this thread).
This is a boundary he is forced to accept. He accepts though that those that choose to come along know what they are stepping into so when people complain about something that touches a nerve for them having laughed at things that might touch a nerve for others, he rejects their complaint as hypocrisy. He also polices them to some extent to check that they really are 'geting it' not using his words as weapons against others."
I feel like I'm sitting in the Church of Jimmy Carr... 
I also found the "trust" comment along with the idea that the poster interpreted that she understood his intent and meaning a bit odd as well.
And the paragraph about parents of children with SNs looking out for people making fun of the children or being distraught over having children with disabilities ... well, it was incredibly condescending. Not to mention ridiculously stereotypical.
The "don't like it, don't watch it" brigade don't seem to think it applies to racial humour, only disablist. Interesting. 
There's a difference between allowing free speech and inciting hatred and bullying of vulnerable children with disabilities, even if it is rather insidious. And I DO think that these type of jokes make it "okay" to many people to make derogatory comments and jokes about people/children with disabilities, which then makes them dehumanised to some extent, which them opens the door for further abuse.
I won't even go into the ridiculous nonsense of the sociological breakdown of satire and the intellectual aspect of the joke... as I personally don't think most people go to a comedian for an "intellectual evening do."
I think that a comedian that uses that type of joke (for whatever reason) shows a disturbing lack of morality, ethics, and intelligence...as well as a distinct lack of creativity... surely he should be capable of finding other socially acceptable things that are funnier.