The opinion is relatively short, and quite readable. Note that the Seventh Circuit is applying Illinois law, which is relatively defendant friendly in this class of cases: "a statement that is reasonably capable of an innocent construction is not [in the absence of evidence of specific losses] defamatory."

Using an academic definition of "replicate," Lott maintains that the passage [which said that "When other scholars have tried to replicate his results, they found that right-to-carry laws simply don't bring down crime"] means that others repeated, to a tee, his technical analysis but were unable to duplicate his results, suggesting that he either faked his data or performed his analysis incompetently.

In [the] context [of a book, Freakonomics, aimed at the general public], it is reasonable to read "replicate" in more generic terms. That is, the sentence could mean that scholars tried to reach the same conclusion as Lott, using different models, data, and assumptions, but could not do so. This reading does not imply that Lott falsified his results or was incompetent; instead, it suggests only that scholars have disagreed with Lott's findings about the controversial relationship between guns and crime. By concluding that this more generic definition of "replicate" is reasonable, we are not assuming that the reader is a simpleton. After all, econometrics is far from conventional wisdom. We are, however, taking into account the context of the statement and acknowledging that the natural and obvious meaning of "replicate" can lie outside the realm of academia for this broadly appealing book.

Sounds quite right to me.

Thanks to How Appealing for the pointer.