George Lucas believed Qui-Gon was wrong to decide to train Anakin Skywalker in Star Wars: Episode I - The Phantom Menace. Many viewers see Qui-Gon Jinn as the perfect Jedi, the embodiment of everything the Order was supposed to represent. He is a rebel against the Council, alone and uncorrupted, a champion of the underdog who recognizes Anakin Skywalker's potential. The reality, of course, is that Qui-Gon is a lot more nuanced; he's as flawed as any other Jedi, and in fact George Lucas considered him even more flawed.
Lucas expressed his own view in an interview with Cut Magazine in 1999 (via David Talks SW). In his view, Qui-Gon shares the same faults as Anakin; he is spontaneous and reckless, with Obi-Wan Kenobi providing him a sense of balance. What's more, Lucas surprisingly suggested Qui-Gon made a mistake in insisting the Jedi should train Anakin.
""I think it is obvious that he [Qui-Gon] was wrong in Episode I and made a dangerous decision, but ultimately this decision may be correct. The 'phantom menace' refers to the force of the dark side of the universe. Anakin will be taken over by dark forces which in turn destroy the balance of the Galaxy, but the individual who kills the Emperor is Darth Vader - also Anakin."
It is certainly ironic that Lucas believes it "obvious" Qui-Gon shouldn't have trained Anakin. The modern consensus is that Qui-Gon was the one Jedi who could have saved Anakin, the only one who truly understood the prophecy of the Chosen One.
George Lucas' Perspective Is Right, and Qui-Gon Was Wrong
The general view is that the Jedi Council was wrong to initially reject Anakin. Lucas takes a different view, though, suggesting Anakin's training was in fact the mistake that doomed the order. It's fascinating to imagine how the Star Wars saga would have played out if Anakin didn't the Jedi; the most likely scenario is that he'd have been taken in by the people of Naboo as a hero, and no doubt he and Pé would have gotten together anyway. Pé wouldn't have held Anakin back when he began dreaming of his mother's death, so this Anakin would never have built up the fear of loss to the cataclysmic degree seen in Star Wars: Episode III - Revenge of the Sith. Amazingly, this is probably the happiest path Anakin could have taken - and he was denied it because of Qui-Gon Jinn's choice.
It's significant that the will of the Force had Anakin brought up on Tatooine, a world outside the Republic, where he wouldn't be found by the Jedi. In his impetuousness, Qui-Gon insisted the Chosen One should be trained by the Jedi - but there's nothing to indicate the prophecy of the Chosen One suggested any such thing. Unsurprisingly, Lucas' perspective on the Star Wars saga is entirely convincing, even if it does run against the general view. Things worked out in the end, of course, but only after a whole lot of chaos on a galactic scale.
Source: Cut Magazine (via David Talks SW)