Essentially, the statement that "The Taleban leader does not allow such acts to be carried out from Afghanistan's territory" does not mean that "I did plan the attack even though I'm not allowed to do that." I don't see how the first statement implies that he lied about it.
Also, I should mention that there have been "recordings" of him saying that he admits doing it, but the audio tapes are very poor in quality, and therefore the voice may have been easily spliced or computer-generated by the CIA to imitate the voice of Bin Laden as best as possible. See this.
Also, I should mention that there have been "recordings" of him saying that he admits doing it, but the audio tapes are very poor in quality, and therefore the voice may have been easily spliced or computer-generated by the CIA to imitate the voice of Bin Laden as best as possible. See this.