Indeed. I checked in darktable, and those have RGB code values like (0.7, -0.1, 0.5) in destination primaries, in this case Rec.709 which are the same primaries as sRGB. Note that this is just an illustrative example.
So you see the green channel has a negative value at any exposure (exposure adjustment is just multiplication of the whole triplet by a constant).
Eventually the negative component gets clipped to zero at the output stage and the result is (0.7, 0, 0.5). The ratio of red to blue is 0.7 / 0.5 = 1.4. This is a magenta with an emphasis on red.
If we wanted to properly correct for the negative, we might first add an amount of white to the signal. In this case (0.1, 0.1, 0.1) suffices to bring the negative to zero: (0.8, 0.0, 0.6). Notice now that the ratio of red to blue is 0.8 / 0.6 ~ 1.33 which is less towards red than the above clipped case. This is how clipping skews the colors.
The latter corrected RGB triplet has a greater luminance than original, but this is easily corrected by applying a suitable gain (multiplication by constant). This doesn’t change the ratio.
In the general course of this thread, I notice that some confusion may be caused because filmic rgb maps the output against display profile while in darkroom and against export profile when exporting. The intention is that you are able to see the actual hues (in the HSV / chromaticity sense) while editing, and those same hues are preserved no matter if you export to sRGB or AdobeRGB or some other encoding.
The confusing part is, if your display can’t reproduce the whole export color gamut, the exported file will look different than the darkroom preview when viewed in a viewer that doesn’t do this kind of gamut mapping to preserve hues (most image viewers, I imagine? Darktable is also one of these when you open an exported image in the darkroom). I could see if there’s any clarification to be made to the manual.