A long time beekeeper told me on more than one occasion it's impossible. I mentioned queen footprint pheromone being only present in the brood box but he insisted that if the bees are in close proximity to the super in one cluster it can't happen, you need wide separation with brood isolated above a couple of supers.
I had a brood box with one or two supers sometime during a flow, and by chance I happened to remove a frame to check the cappings. I thought it was brace comb at first but there on the frame was just one queen cell with a heap of royal jelly and no other eggs or unsealed or sealed brood.
The hive was queenright and there was a normal brood pattern and plenty of space. The queen cell was removed to a mating nuc where it emerged and was successfully mated.
My guess is that an egg got moved intentionally or otherwise on a workers back or leg and a quirk of nature did the rest.
