This really has no bearing as to the raw file but that the raw converter thru the conversion into a viewable color space and the limited gamut is causing the clipping
depending on what color space is used there are very different outcome to how that image will be displayed within the color space.
So how can you know what is causing the clipping? is it the WB is it the color space or can it be behind the scene processing?
You really need to understand that the histogram in camera and the raw converter is not a raw histogram. that histogram is based on the processed image, one of the processes is that it is placed into a color space, how large that color space is limited to is by design. If I use a smaller color space and that is what causes the clipping it will show up as clipping
youtu.be/lke4XfSU1lI
Here is an image, the wire frame is a color space, everything outside will show as clipped in the raw conversion, while the raw file would allow me to construct a image with much of the colors that would not be limited to that color space.
Again if the histogram in the raw converter is based on the outgoing image and the size of that color space how can you use that converters histogram in a way to judge what is happening to the raw data?