It can be very easy to decide that a plant is labelled incorrectly: the flower is white when it should be red, single when it should be double. It is almost never as simple to decide what it actually is.
There is in Section 1G a low, wide spreading plant that is flowering white in December. It is labelled ‘Chansonette’.

The offending label

The true ‘Chansonette’ has semi-double blooms about 6cm across and cerise in colour. It would be flowering at about the same time and its foliage would be very similar.

Camellia x hiemalis ‘Chansonette’

In the collection records the bush is said to have come from Coghurst Nursery, one of two planted in 2002. The other plant is growing in a different place, struggling somewhat and not in flower.

It is not neccessarily the case that the nursery supplied the wrong plant but it does happen. They may have bought in young plants, grown them on to a saleable size but not seen some or any of the batch in flower.
Looking at their website reveals that they list only three pure white sasanqua type camellias and two of them are clearly different. The third, ‘Kenkyo’, looks to be a very good match.
Looking at pictures I have taken of ‘Kenkyo’ and every other picture of it that I can find, in print and online, I am fairly confident that I have a match.

One of functions of National Collections is as a reference against which unknown material can be matched. To be fit for purpose they have to be accurately labelled. The question is what level of certainty is acceptable?

To jail a man for life the standard is beyond reasonable doubt, to win a civil case it is on the balance of probabilities. Both tests will mean different things to different people. The label on a plant could be very important to one person and of no interest whatever to another. Some gardeners keep  notebooks of everything they plant and keep labels on the plants, others throw the labels away at planting time and are happy not to know the name.

Is it better to have a name on a plant that is probably right than one that is definitely wrong? Is a label that says Camellia sasanqua var. any use to anyone? What is the worst that could happen if it were wrong?
I want it to matter enough to justify making the effort of getting right in the first place, otherwise why bother labelling them at all?

I am told that these sorts of thoughts make me a systemizer; which I don’t think is a compliment. Shakespeare would not have sympathised, “a rose / By any other name would smell as sweet.”