Thanks for the clarification, Chris.
When I said surrounded by pollen, I maybe should have said surrounded by combs of pollen. Apparently - I didn't see it for myself, as it wasn't my colony and I wasn't in the area at the time, or I'd have gone to have a look! - the colony was absolutely stuffed with pollen. I can't agree that pollen weighs "next to nothing", as once it has been prepped for winter storage, it does weigh in the comb. Not as heavy as honey of course, but, as happened here, it can give a misleading impression about the amount of stores within the hive - if the guy had looked he would have seen pollen stores, and not honey....
My real point is that taking a quick look in the brood box to see what is going on is very illuminating - particularly if you're not sure what is going on inside. As I said, I inspected mine 10 days ago - went into the brood box briefly in all of the colonies - and all was fine. I suspect that if the disturbance had been threatening to the bees, they would have seen me off. As it was, I didn't even need my veil up. My perspective is that there is no point in waiting til some arbitrary date on the calendar or until it is comfortable to be out in a t-shirt, to look at dead bees.