The coroner Nicholas Gardiner would, one imagines, have become aware of the Inquiry on the date it was set up ... the day of the discovery of the body (18 July 2003). He must have been bemused, even concerned, about this. How was his process going to dovetail into an Inquiry if at all?
I suggest that two things would have become apparent to Mr Gardiner quite quickly: firstly that this was going to be an ad hoc inquiry without the sort of statutory provisions that an inquest has to have. Secondly that Hutton was a person in a hurry: it looked as if he would be taking evidence long before Mr Gardiner would be overseeing his resumed inquest. On that second point, the coroner has stated that he had anticipated carrying out the inquest in September. Even by the first of that month Hutton had listened to about three dozen witnesses.
It looks as if it was on the 4th of August that the coroner had the first formal indication that the Lord Chancellor was invoking Section 17A (I'm not sure if this date was when the letter was written or received). So, about ten days before the inquest was indefinitely adjourned Mr Gardiner was aware that Section 17A would be invoked whether he liked it or not. Lord Hutton would have been kept in the loop on this.
In Blair's first government in 1997 Falconer became Solicitor General. It was followed by a stint as Minister of State at the Cabinet Office and he took over the responsibility for the Millenium Dome after the first resignation of Peter Mandelson (Somebody had to do it I suppose!). The possibility exists that Falconer had some input into the mammoth Access to Justice Act 1999 with its 110 sections and 15 schedules. This act was the origin of our Section 17A and it's not impossible that Falconer had some part in producing the act, even the content of section 71 which was to become 17A in the Coroners Act.
An intriguing question now is whether, when Falconer set up the Hutton Inquiry, he was aware of the availability of Section 17A ... which he could use to stop the inquest in its tracks. If he wasn't at that moment then I'm sure it didn't take him long to find out.
Hutton and Dingemans visited Mrs Kelly and the family on 26 July. One of the objectives it seems was to get Mrs Kelly to give evidence at the Inquiry. At that time she might well have expressed concern about going to the Inquiry if she was aware that she would almost certainly be giving evidence to an inquest. But what if Hutton could have assured her that there wouldn't be an inquest, then the trauma of going to the Inquiry would be lessened I would think, particularly if Hutton was able to tell her that her testimony could be delivered by an audio link. Before going to Southmoor it would certainly have been useful from Hutton's perspective if he could inform Mrs Kelly: 'Don't worry, there won't be an inquest'.
My belief is that the decision to sideline the coroner was taken either on the 18th July or shortly thereafter.