On one hand, I'm more likely to believe Lehrer now, because he will be writing for a large audience of people who would love nothing more than to catch him out again. Very few authors will publish under the kind of scrutiny he will, for a few years.
On the other hand, I'm less likely because he's a shameful liar, and I don't want to contribute to his livelihood as a liar. I mean, if he was a barrista I'd give him a tip, but it's hard to lie about a latte.
So I suppose when you add these two things together I'm more likely to finish my goddamn software project.
There's an ambiguity in your comment. You set up "more likely to believe Lehrer now", and then in the second paragraph go on to say:
"On the other hand, I'm less likely [to believe Lehrer now] because he's a shameful liar, and I don't want to contribute to his livelihood as a liar. I mean, if he was a barrista I'd give him a tip, but it's hard to lie about a latte."
It strikes me that the part I have italicised is an entirely separate point, disconnected from the "two hands" you had established.
I point this out in such a pedantic way because I think this separate point about not wanting to contribute to the livelihood of a liar is a particularly interesting (moral) one which could be elaborated on. Also, I found your barista analogy entertaining!
On the other hand, I'm less likely because he's a shameful liar, and I don't want to contribute to his livelihood as a liar. I mean, if he was a barrista I'd give him a tip, but it's hard to lie about a latte.
So I suppose when you add these two things together I'm more likely to finish my goddamn software project.