The thing is, even with genetic testing, the human aspect in terms of sourcing and verifying is more important and in this particular case is where the issue actually is....so it's still going to be hard...
Simply put. After you test 20 cuts of OG, you still can't tell which once was the original...or it's still very, very unlikely you'll be able to tell which is the original. You can verify if they are all similar, and what may not be an OG, but DNA poses no lineage or historic information unless it can be tied to real life events...
If we definitively knew which was the original then you could have a much easier time telling which ones aren't closely related, but unless we have proper sourcing, it's a crap shoot.
And that's the rub. Too many claims on who has the original, and more popping up, like that Supadipshit. Hell, he has given three differing stories alone. He's even said it had Hawaiian Web leaf in it. Then there is the Bubba dude from Florida that claims he found the OG in Bagseed, and it pollinated a NL cross from Humbolt (that he got in New Orleans) to create Bubba Kush.
Just more convoluted bullshit from wannabe cannabis legends.
Don't get me wrong, I'd love to know the truth. But separating truth from bullshit is nigh impossible. And I'm afraid that the truth may never be truly told. But I do feel testing will at least give an idea what is likely in it. Even if we can't figure out who did it.
To me, what it really is (genetically) is more important that who popped the bagseed.