Well, that's not quite what she said, but it's the import of it. I was astounded at her reaction in the last hour to Fred Barnes's mentioning of a piece of information that's pretty much common knowledge. She grilled him about where exactly he might have heard it, and of course he couldn't remember. She then said that she'd never heard of such a thing, and he said he'd heard it several times but had not confirmed it personally. This piece of information was that Lieutenant George W. Bush had volunteered to go to Vietnam during his National Guard service. The fact is that Barnes was right. Rehm was wrong. This is public knowledge. The colonel who swore Bush in has gone on record saying that Bush had indeed asked to serve in Vietnam but was turned down because he hadn't yet put in enough training hours. He'd completed only 300 out of the 500 needed. It's possible that this colonel wasn't telling the truth, but it's a matter of public record that he said this, and that's all that Barnes had claimed.
A quick Google search by one of Rehm's staff could easily have found something on this and cleared it up by the end of the show. Instead, they allowed a caller to come on claiming that Barnes was irresponsibly spreading false rumors, with no moderating of this claim by Rehm. They do screen their calls. They could have chosen a different caller. I think this counts as irresponsible journalism. Even if they didn't have the resources to check up on it immediately (which I doubt is the case; a show like hers probably has staff members who can do quick fact-checking on the spot), they should have kept in mind that Fred Barnes is a respected journalist who doesn't just make things up. But she didn't want to believe what he was saying, so she assumed that he had to be wrong. They should not have allowed him to be slandered on the air in such a way without at least saying that they should take the time to investigate these claims before calling him a liar.
Update: I found a letter sent by someone who knew Lt. Bush that includes mention of this here, in the third paragraph. It sounds entirely plausible. Some new plane was out, and Bush thought it was really cool. He was interested in the program that would have involved using these plans in Vietnam, but he didn't have enough experience yet to do it.