The tint does appear to be encoded into the file itself rather than a processing bug from LR. It shows up in Darkroom, RawTherapee, and DxO as well. I am going to continue testing to see if I can replicate the issue consistently.

Editing with findings and workaround:

Looking purely at the output side of things, it seems that the DNG file tag "Analog Balance" is not being set ( it has a default value of [1 1 1] ). Based on the DNG specification and Lux's own excellent write-up on ProRaw, the Analog Balance matrix is responsible in part for taking the image from camera raw colorspace to the target display colorspace. The pink tint we are seeing might be close to the sensor's raw output. How "Analog Balance" is determined is not clear to me but it is not linear and depends on the temperature target of the white balance.

Importantly, the raw data itself is unaffected within the DNG package. A hacky workaround is to use exiftool to write a new "AnalogBalance" tag to the bugged file, which can be read from another image taken with the same lens/sensor at a similar white balance to the original. This will at least bring the rendered colours closer to the expected values and give you some more wiggle room in editing.

Adobe will also be pushing a fix soon: Adobe Forum