Jon,
As luck would have it I was busy chopping down a tree with the chainsaw and a few bees started flying around me. Well, on standing back I observed mini nuc in live action AVM (perhaps)

this is what I saw, the bees in the mini all poured out of the small round hole entrance and began to circle, I watched to see if i could see a Q but nothing at all. Some returning field bees seemed to sense that someting was wrong and simply circled around the entrance hole then flew off to i assume join the swarm. There was no activity at the nuc for about 5-10 minutes but you could see the bees circling around the garden high and low from side to side over an area of about 25m square. I did not notice any sign of a cluster. After 10 mins or so the bees returned to the box and began vigorously fanning, I watched closely until the whole event was over.

My conclusion is that this is an attempt at absconding by means of some sort of swarming behaviour and is nothing to do with queen mating as there in this case no queen flying involved at all