Assuming Neil Fox's show this morning was voice-tracked, there was no obvious way to tell. In fact, at one point, he punted for requests 'which we might get on before 12', which is a bit naughty.
It was obviously recorded reasonably close to broadcast, as he had a fairly accurate weather forecast and talked a lot about the warm weekend ahead. It sounded good, and very in-tune with London life and the time of day - not a million miles away from the classic Capital vibe they're aiming for.
I wish the station sounded like that all the time.