[Marsh.]

I really don't understand how someone leaving one job for another is "mysterious".

If he'd quit and vanished into thin air then maybe.

But "runner leaves show for another show on itv that is a step higher and more money" is not a story. Runners are literally people wanting to work in the TV industry, at some point they are going to work their way up into other jobs in the industry, writers/producers/actors/presenters etc etc etc. This is not news.