In journalism/media school, we're taught "show, don't tell" in both our news and creative writing courses. You want to use detail to set the atmosphere/tone without flat out saying it.
I have heard that this advice is given for news, and I think that this is unfortunate.
"Show, don't tell" is not necessarily appropriate in news. News and writing for entertainment serve such radically different goals that it's worth carefully considering to what extent the same methods and models fit both.
When someone reads creative writing, they derive enjoyment from the mental reconstruction of the scene, the characters' intentions, etc. The writer may want the story to afford multiple interpretations and reward multiple readings.
But with news, the reader often just wants information. They may not be able to devote their full attention to the story, and they may lack the necessary contextual information to connect the dots you have laid out before them. The reliable transmission of information is more important than stimulating or entertaining the reader.
It depends on how obvious the lie is. If someone says "The earth is both flat and made of cheese", they are so obviously wrong that you could afford to just rely on the reader's common sense. But if they say "the economy grew by Y percent for the first time in Z years", it's unlikely the reader has the facts necessary to recognize this as a lie immediately on hand.
For less obvious lies, it would be helpful to lead with the truth (see the primacy effect on memory). After stating the truth, then you can say "but politican X said Y".
This is lampshaded in the Futurama episode "The Devil's Hands are Idle Playthings", when Robot Devil complains about Fry's opera, saying that "you cannot make your characters just say how they feel. That sloppy writing makes me so angry!" (Quoting from memory.)
