Just want to re-up this over having the same damn conversation again, comfortable as that is.
Very interesting data point.
The notion that uv only raises thc is scientifically dubious to say the least. I think it's likely the people who say that are just wrong. Not just based on this data point, but it fits.
The only way this thc-exclusive claim would be true is if uvr8 only modulates thcas. I don't think that's true. I think it modulates the common precursor (cbga) by influencing the processes on that chemical's precursors. Whether it also influences the production of thcas idk, but i doubt it's exclusive. An explanation for why it doesn't raise cbd is it hasn't been tried with functional genes for both thcas and cbdas (in the papers this claim is based on). I would expect a plant without a functional thcas gene to either try something else (secondary sunblock processes being heightened) or suffer pretty badly under uv and burn off a lot of chemicals in its tissues.
I think a uv study on a 50/50 strain would yield another interesting data point.