The case against him was always as I expressed it in that original post:
as Andrew Neil explained on Newsnight yesterday evening, it is inconceivable that Coulson would not have quizzed his reporters about their methods when they came to him with big stories.If this affair, as appears to be happening, now comes to centre on relations between the News International and the police then it could still turn into a huge scandal.
An editor has to be able to judge the truth of a story and how defensible it would be in court. The way the story was come by is central to both these question.
In any case, I can claim to be more prophetic than Guido Fawkes, who has always argued that Coulson would survive. Try a post from 11 December of last year:
What has been a politically motivated attack by enemies of the Murdoch press was bound to fail without a smoking gun, however much they huffed and puffed.