biggest goof
The biggest goof in the movie was identified by Adrian Cronauer himself, who said that apart from the fact that he was a morning DJ on Armed Forces Radio in Vietnam and opened his show with that "good morning" yell, everything else in the film was inaccurate, at least about him.
Even the "good morning" yell was different -- it was "Good Morning, Iraklion," which was the name of the air station from which he broadcast. The restaurant bombing was also sort of accurate, but he wasn't pulled from the place at the last minute: He witnessed the bombing from nearby.
Cronauer said the higher-ups didn't oppose him. They were more apathetic than anything else. And his humor was situational, not the kind of rapid one-liners that Robin Williams delivered. Williams was playing himself, not Adrian Cronauer. In fact, says Cronauer, "if I'd been that funny, I would have been in Hollywood."
Moreover, Cronauer has been a life-long "card-carrying Republican." He was very active in Bob Dole's and George W. Bush's presidential campaigns.