I agree on wind being a huge factor in distance. Do you honestly not think wind is the main reason a 13 year old throws almost 800 ft? I can throw 450 on my best drive. Add a tailwind and that disc will EASILY with out a doubt go at LEAST 200 ft more, maybe more.
It's hard to argue though. I don't know anywhere indoor thats 800 ft long, and tall enough to throw a disc. Which makes me believe there will never be a "real" distance record. Until than wind will be a factor. We also have to keep in mind this is an object in the air. So I can understand people saying wind isn't a factor, but a part of the sport. However, I don't think that makes a "distance record" a true measurement.
If someone threw a baseball as far as they could and it somehow found a gust of wind strong enough (unlikely) and it carried a mile away, would it be safe to say that PERSON threw that baseball that far? No. He threw it X while the wind carried it X. Big difference. This is the same here. Yes, a disc has better flight characteristics than a baseball and the winds it's friend, but that doesn't show how far said person himself threw it.