Joe didn't realize that that f-word in the report was off the air.
He didn't call anyone that word or use the word directly, he was referring to the use of the word by others.
It is a vulgar phrase, but let's grow up about this, Jesse Jackson used it directly to much greater effect and it was repeated on-air many times by the media because it (the f-word) was so news-worthy in that context.
I thought Cheney used it well for Leaky