The other third didn't lie, or perhaps forgot, or you're lying to me about your lying, which is very, very devious.  This fits with a lot of the research, which suggests that lying is very pervasive.
剩下那三分之一的人没有撒谎，或也许是忘了， 或是你们对我撒谎，说你们没撒谎，这真的非常， 非常狡猾。这正好符合了大量的研究， 表明撒谎是无处不在的。