Ruairi is about 13 now. I see the klaxon has sounded! What a relief.
SOC was involved with TA before during Vanessa Whitburn's long reign. He was a producer, which involves storylining. My understanding is that the storyline is ultimately set by the Editor, after prolonged discussion between the whole team (producers, scriptwriters, Editor, archivist when they had had one). Then it has to go the head of Radio 4 for approval.
VW was editor from 1991 to 2013. She came from Brookside, of course, but hadn't been there long.