The way my friend thought it up is a mystery to me I'm only posting cause I wanted others opinions on it. But now that my mind's been wrapped-up into this I can say the possiblity is there. With Kakashi already stating the relationship between the Uchiha and Hyuga, the relationship is already there. The fact of the matter is where does the relationship come in at. I'm not saying the Hyuga gave birth to the Uchiha, we already know the sage did, that's not an issue. What I'm trying to get to is the Hyuga's "mutation" known to be the byakugan and where did it originate. The way I see it is the the Uchiha mixed bred with another clan, The Hyuga. Making their KKG even better, allowing the abilities of seeing chakra, and the specialized points of flow, and x-ray vison. Allowing them to utilize their taijutsu so efficiantly. As it is noted that the Hyuga's eyes aren't cursed like the Uchiha's are and I believe this due to genetics. Just like not all Uchihas are held by the hatred (Shisui/Itachi). Maybe osince their not Uchiha, their eyes can't carry the curse along. Or the fact that their eyes aren't strong enough to hold the Juubi's hatred.
Whatever the reason, their eyes in the basic activation are similar 3T and byakuga, and it's not too far fetched of an idea to think them related. I would be looking for something the Hyuga, as a second activation... even if It is that Taoist theory. Give them something.