Thanks!
I did have it in mind that it was about 12:30, but I looked back at news for the day, and BBC had taken off the time stamp, and SKY was the one I found (maybe it's showing a time it was revised?)
I still make it 1-2 hours to contact everyone, arrange the plane, get to an airport, and take off (Charles rung at 12:30, plane needing to be leaving at about 1430)
I'm really not sure that leaves much time for a row that caused delay
How long it takes to alert key family would very much depend on where they were and if they have a phone (or a private secretary) with them. If off walking dogs, riding, something private or whatever it could take a while to track them down