Justice Asher did not find the instances of contempt to be deliberate and in all but one case described them as "minor but not so trivial as to warrant a finding of no contempt".
"They were more than technical."
It was the publication of information from the settlement conference which he described as "more serious", labelling it an "accidental contempt of court by Slater but one that was the result of significant carelessness".
Justice Asher said Slater had testified he had told his wife about details from the confidential conference and that she had published the article on the Whale Oil blog while he was on a plane to Europe.
Justice Asher said Slater was careless in telling his wife about the conference without warning her of the confidentiality - and had breached confidence by telling her about it at all.
In regard to articles which mentioned Mr Blomfield, Justice Asher said there were electronic techniques which could be used to keep certain words and names from being published.
He reminded Slater he had claimed to be a journalist and been found to be a journalist by the High Court.
"In these circumstances there was a particular duty on him to ensure that the undertaking was complied with, and that reasonable measures were put in place by him to ensure any further postings on his site by third parties did not breach the undertaking."
It is one of a series of court cases in which Slater is involved. He is the target of the defamation action by Conservative Party founder Colin Craig and is challenging an injunction brought by the NZ Nurses Organisation.