Therefor it follows that included pollens are not a strict proof of nectar origin.
It most certainly is if the pollen is derived from flowering plants in China, or the like but the honey is claimed to be local.
It was a superb method to provide evidence of the Norfolk (I think) honey seller who cut their honey with imported material and sold it on as 'Lavender' honey.
If the pollen is from a typical plant on which the bees will forage for nectar, one can assume there is likely to be nectar contamination, perhaps only a small amount collected by some of the bees. Now if that plant flowers at another time of the year, it would indicate a slightly different scenario.
The only thing is that one cannot argue that it is not there, only explain the truth (and yes, cover your backside with some small print, if that is allowed)
There are lots of 'ifs and buts'. Remember, even if a product is nut free, a food processor has to put out a warning for possible contamination if the production line is used for other products, which do contain nuts. An extreme comparison, I know, but the trading standards person probably had nothing better to chase that day or week or whatever. Pick on a beekeeper, have a practise for a new inspector where they know how easy it is to have 'less than perfect' operating conditions.
Me, I would single out those bees from that particular hive and sack them on the spot. Line them up against a wall and shoot them with fly spray! Fancy them not doing as the beekeeper wanted!! Teach them a lesson (er?) and show the rest the consequences if it happens again. That's what I would do.
Regards, RAB