Well, it is a fact that it is their opinion. 
And at least some opinions are based on that person's interpretation of facts.
But many facts are based on that person's interpretation of reality, which may not even exist in the first place.
So we're all fucked.
And at least some opinions are based on that person's interpretation of facts.
But many facts are based on that person's interpretation of reality, which may not even exist in the first place.
So we're all fucked.