[Stooky Bill]

I see it had a radio simulcast too - I wonder how much effort they went to to keep them in sync (compared to how this kind of thing would have been done in the olden days!)

They wouldn't try at all, and there's not really any need to, there's not the expectation of people listening to the debate on Radio WM in stereo with the TV sound tuned off. And of course theres no way to do that these days.

It'll presumably be the same source as TV were broadcasting on a studio OS, unless they had a seperate radio copy and played that.

Doesn't Question Time still go out on 5Live as a simulcast with BBC1 ?