Thus it is with Brian Williams and Bill O'Reilly.
(I cannot fucking believe I'm defending Bill Fucking O'Reilly of all people. Fuck.)
Williams fucked up in crossing the war stories line of lies. I've been in enough helos to know they're not the most comfortable ride in the world, but a crash in one of those fucking things is pretty distinguishable as to whether one was or was not in one. Williams was not in a helo that was shot down, and said he was. Blatant lie by a reporter. Back in the day, Cronkite would've beaten the shit out of Williams in the alley behind the CBS building before lighting a cigar and using the smoke break to lecture him on journalistic ethics.
O'Reilly, on the other hand, has some nebulous language surrounding his time covering the Falkland war back in the 80's. Was he on the islands proper? No. No reporter was. He was however in Argentina, in Buenos Aires along with every other reporter, and as such balls-deep in the riots following the British victory. Semantics, yeah, and politifact has rated him as half-true as a result.
That said, if being in Buenos Aires during the fighting and postwar riots doesn't count as being in the war zone, then neither does covering the Iraq war from the comforts of Camp Cupcake, Anaconda, or the Green Zone. In which case, I think a lot of reporters out there may have to make some adjustments to their cred.