Color picker vs highlights recovery
http://tech.kovacs-telekes.org/files/DSC_4684/DSC_4684.NEF is the raw image, it shows blown highlights on the wig.
Opening the image with all modules cleared except for those shown (those that can't be disabled + exposure and orientation), applied a
-1EV correction. The result is:
It shows two 'live' colour samplers (area, Lab mean). The blown-out part has a lower L value than the other, darker part. Also note that the bright highlight is sampled as purple, not yellow.
Switching from 'reconstruct color' (samplers1) to 'clip highlights' changes the image dramatically:
However, the displayed samplers remain the same.
It seems to me that the highlight sampler shows the 'clip highlights' value, no matter what recovery method is selected.
You can see something similar if you open the tone curve tool:
sampling inside the clipped highlight will give you an L value around 76, and inside the darker path around 80.