I saw this today in an article talking about difficult paradoxes. But I cannot see how this is difficult to grasp.
This statement is, by definition, false. Either he has told a truth at some point in the past, or he is telling the truth now. That does not make this statement a lie, merely false (and provably so). Lies may be true (if I say I have a million dollars when I believe I do not, but upon checking my bank account find that I have won the lottery at some point prior to making the statement unbeknownst to me, then the lie I believed I was telling was in fact a true statement; it does not change the fact that I was lying at the time I spoke it), and truthful statements may be false (again, if I say I have a million dollars, but find out later that at the time I spoke that my wife had spent it all prior to my making the statement, then it is a false statement, but one I did not lie about). I suppose the problem comes from language not being a logical construct where lies must always be false and truthful statements must always be true.