I wasn't at this particular briefing, but based on my experience it'll have gone something like this.
RD & the DET will get an invite after one or both of them have asked for an interview - I know Steve Nic had asked on this occasion, not sure about RD.
There's generally a bit of an off-the-record conversation before the actual interview gets underway. It's not like post-match where the manager will walk up and the conversation starts immediately.
As there's no point asking the same/very similar questions twice, radio will kick-off and the paper are welcome to use that too. This is standard for interviews/press conferences, and that's why the DET transcript is the same as the RD interview.
After the radio has finished, the DET will generally follow up with any extra questions, or to clarify any bits that need it.
Then everyone will agree when they're going to run the stuff.
And that's how the sausage gets made 👍