Despite the claims that George Lucas had Star Wars all plotted out from the very beginning, the evidence readily available in the series itself suggests that is no more than an urban legend introduced to make him look better. Sadly, for him, A New Hope contains so many major narrative inaccuracies in retrospect that the image of Lying Obi-Wan Kenobi has become a meme in its own right.
Some of it is forgivable: Star Wars was a bold gamble after all, and there was no way anyone could have been all that confident of a franchise with any kind of longevity would spring forth from it. But the one thing you should be able to count on with a film so heavily steeped in lore is a commitment to the details it established.
If that's what you're looking for, these really aren't the films you're looking for. The films have bigger inaccuracies than just what Kenobi said in error and examining the evidence paints a picture of a universe built as much on lies as on the Force.
To quote Obi-Wan: "...you're going to find that many of the truths we cling to depend greatly on our own point of view." But then he would say that, the dirty great fibber.