In my example, you can't have an opinion on what the unemployment rate was. It's a factual number, not something open for debate and opinion. If you say it was 9% three years ago, you don't get to just claim that is your opinion. You are wrong. If you think it's under 2% now, that is not your opinion. You are just wrong. If you continue to repeat it, you are still wrong. And there's a good chance you keep repeating it in order to rile people up...AKA, troll. I didn't say it was about the poster's position, but rather the continuous posting of false information after being told it's wrong.
Now, if that isn't trolling, then it's pure stupidity. And that may be worse.