actually the story plays out that qui gon was the only jedi of his time to recognize the flaws in the order
keep in mind he also stays on the good side even after his death into episode 3 and beyond
qui gon was the first jedi to learn how to preserve his spirit from becoming lost to the force
(yoda spoke to his spirit in ep.3)
and he obviously continued to coach obi wan and yoda during the post ep.3 to pre ep.4 era so that they could do the same, and who knows what other knowledge he would've passed on