The leading case in America governing libel against public person held that recovery for damages due to a libelous statement could be had only upon proof that the author acted “with ‘actual malice’–that is, with knowledge that it was false or with reckless disregard of whether it was false or not.” New York Times Co. v. Sullivan (1964).
The reason that most public persons do not sue for libel is because the burden is so high: They have to prove the libelous statement was untrue, rather than the person making the statement proving that it was true. Then they have to prove that the person knew it was false or acted with reckless disregard of whether it was false or not.
Assuming that Rush can prove that he never uttered the statement (a dubious assumption–how do you prove a negative? Although it seems incredible that with millions of listeners nobody noticed the quote until 2005), Mr. Huberman’s body of work provides ample fodder for proving his malice. Just look at some of his books. “The Bush hater’s handbook…”; “The GOP hater’s handbook”; “The quotable atheist” as well as “101 persons who are screwing America.”
A person who has no known bias or animous towards another can just exclaim innocence: “I didn’t know the Wikiquote was bogus!” It becomes much less believable when that person has shown such hatred towards conservatives and Republicans in numerous books. I would say that the “reckless disregard to whether it was true or not” standard should easily be met if Huberman relied on Wikiquotes. Nobody in their right mind would rely on that. Anybody can go in and insert quotes, without attribution, as happened in this case. Absent some other purported source, and assuming Limbaugh can prove that he never said it, I’d say Huberman better hire a good lawyer.