There are two answers, quickly.
Russia has become an expert in creating completely fake news. They've used scenes from video games in the past that they've tried to pass off as real television news reports.
The other thing is that Russian state media doesn't only broadcast through RT. That's not the only platform they rely on. They rely on online platforms, whether it's YouTube or their own website, and a lot of the content that appears there is shared, as you say, very widely on platforms like Facebook, unfortunately, Twitter and others.
They don't rely just on that television medium but on online media. The problem is that the information on those platforms gets shared very widely.