In response to Emerson's review, O'Reilly said that the mistakes, which he numbered less than her findings at just "four minor misstatements" and "two typeset errors", had been corrected in subsequent printings.

[8] O'Reilly called the controversy "a concerted effort by people who don’t like me to diminish the book," said that Killing Lincoln was "honest," and wished all students would read it.

[4] English-language, first-edition hardcover print copies containing errata material can be identified as such if they contain the following:[3][9] Additional errors of fact were listed in a review by historian Kate Larson of the University of Michigan.

[12] While finding fault with the accuracy of the work at times, Larson notably adds, "well-written narrative offering a quick read for a general audience....

O'Reilly told USA Today in a phone interview published in the September 29, 2011 issue that he talked with producers ("big hitters") about turning the book into a cable television special.