When was the last time 'Network Recall' was used?
The regions were ordered to bail out of a lunchtime bulletin on 9th April 2003, according to some old posts on here. That was close to the end of the opt so regions would have been listening to network talkback for the count back to network, which was suddenly a lot sooner than expected. Leeds crashed out of the weather forecast, apparently.
On that occasion the presfax based auto recall wasn't used, and I believe some of our insiders have said it doesn't work on the digital distributions - although I guess with Central Coding and Mux they could yank a region off air if needed.
I'm sure the palace PR people would have a hand in when the notice goes up at the Palace, and would be aware that waiting half an hour to avoid the opt and make the announcement afterwards would be a good move.