That's pretty speculative given the amount of extra time a smoker might spend outside - combined with another speculative idea that small amounts of sun exposur

That's pretty speculative given the amount of extra time a smoker might spend outside - combined with another speculative idea that small amounts of sun exposure has a meaningful impact on outcomes. Seems more likely that nicotine itself might have a direct interaction, or that there is no benefit at all, and it's all just noise in the data.