His defence is that Gilligan said the wrong thing in his first unscripted broadcast (not that the BBC admitted that at the time) but then his scripted stuff was all right.
This is not the case, as was established by the Hutton inquiry, and I look forward to reading Marsh's full account in his book. For those who do not remember, Gilligan made three allegations in the scripted version of his report on 29 May 2003:
• that the dossier was, in words attributed directly to Gilligan’s source, "transformed in the week before it was published, to make it sexier";
• that this transformation "took place at the behest of Downing Street" – Gilligan’s words paraphrasing his source, and elaborated by him in the Mail on Sunday, 1 July 2003, putting Alastair Campbell’s name in his source’s mouth;
• the forty-five minutes statement, in words attributed to Gilligan's source, "was included in the dossier against our wishes, because it wasn’t reliable; … we believed that the source was wrong. Most people in intelligence weren’t happy with the dossier, because it didn’t reflect the considered view they were putting forward".
The Hutton inquiry found that the dossier was not "transformed" in the last week. Nor was it true that "most people in intelligence" were unhappy either with the forty-five minutes point or with the dossier generally. The intelligence services corporately, in the form of the Joint Intelligence Committee, approved the dossier and approved the wording of the forty-five minutes point, however much a few individuals at a lower level, including David Kelly, may have disagreed with its inclusion.
It is also rather transparent of Marsh to attribute the allegations made on the Today programme to Kelly ("Dr Kelly's allegations") when he should know that no one knows precisely what Kelly's views were, except that he supported military action against Saddam Hussein.