That's an interesting notion - that lies don't matter as long as you're honest about something else that's more important. I tend to think that when a person lies about something, even an incidental thing, it goes to the person's credibility. For example, Bellesiles always defended himself on the ground that the probate records that he was accused of distorting or falsifying were only a couple of footnotes in a huge book. But if he lied about those, I think it's hard to trust the rest. And Clinton and his defenders always said it didn't matter if he lied about extramarital affairs, because it was incidental to the really important thing - how he did his job as president. But lies matter. Credibility matters. Don't make excuses for a liar like John Lott just because you like some of his conclusions.
I note a disingenuous reluctance to confront Lott's original study. Methinks you have a serious anti-gun agenda.