I don't think sacking his is an appropriate sanction.
It was an offensive remark delivered carelessly by one tv star to another - hence the massive interest.
I do believe that he should apologise - as he has, and the two people involved have accepted it, and moved on. There is nothing to be gained from sacking people for a simple lack of judgement - or we would all be getting sacked on a pretty regular basis because it is human nature to speak without thinking occasionally - hands up anyone who has never felt the silence left by an inopporrtune comment in a social / work situation.
There is no parallele with Carol Thatcher who it appears saw no wrong in her remark, and refused to apologise for it.
Given that her mother possess both bottomless arrogance, a total absence of a sense of humour, and the utter inability to accept that anyone's alternative viewpoint is worth breathing for, we should accept that she is genuinely bewildered by the uproar her comment caused - but there is no place for someone like that on publicly funded television, so she was offered the chance to apologise properly, refused, and got sacked.
Anto Dubeke was careless and thoughtless, but enough of a mature individual to accept his offence caused, and make ammends. None of us can really expect, or in the same situation, do any more than that.