The Prime Minister has a bit of a track record of saying what he thinks in interviews, which is refreshing but occasionally lands him in trouble. I suspect there were some of his advirors who were thinking "oh no" as he made those comments about the comedian Jimmy Carr.
Certainly talking about morality, as opposed to legality, always opens a can of worms.
It also didn't look great when he refused to be drawn on the tax arrangements of his friend Gary Barlow, regardless of whether or not they are similar to those of Jimmy Carr.
We are likely to get months and months more of these kinds of accusations flying around about Mr Cameron's friends and colleagues and their various tax arrangements.