What you have to ask yourself is why? Is Ed Lake lying because of his ego, or because of his ideology, or because he's hoping for financial (or social) gain?
But that he's lying is clear; outlined in black and white with direct quotes above.
It could well be the latter, plus the bonus of all the attention he apparently gets from members of the press.
The best way to get attention from the major left-wing media is to reinforce their biases and stereotypes. And in this case, we know that the media desperately wants the anthrax attacks to have been perpetrated by a conservative American type. Anyone crying out "hey media, do you think perhaps it could have been Islamist terrorists" will just simply be ignored, because it doesn't fit well with the agenda.
But personally, I'm much more interested in why elements of the government are lying than why Ed Lake is lying.