How is the 'As Shot' White Balance value calculated in ART?

Hi,
“As shot” takes the channel multipliers from the image metadata, as recorded by the camera. The conversion to temp/tint is an approximation, and there are multiple slightly different methods to do it. Also, it depends on the camera to xyz conversion method used (in the case of art, a simple matrix for what concerns wb). It’s quite likely that Panasonic is using a slightly different method, so all things considered I’d say that the values you get are not terribly off…
Bottom line, what you get in “as shot” mode should correspond to what you set in the camera. If you have (visual) evidence of the contrary, I would consider that a bug.

HTH