When you read that on a newspaper you know that you're reading a newspaper and they tell you that they've talked with people that allegedly told them something different than the official line.

This doesn't happen with stuff like "no, no the Senate actually didn't pass that law yesterday" that are a matter of obvious public record.

If you're acknowledging a newspaper as a potential source of truth, you're no longer acknowledging the government as the sole source.

I'm going to put it this way: "reputable" newspapers generally want to influence opionion (lie) in a somewhat subtle way. Publishing trivially disprovable falsehoods about official acts isn't how they act, so you can generally trust the parliament-does-something -> official act -> newspaper writing about the official act custody chain insofar as the official act actually existing.