Actually that’s not necessarily true, one might even say it’s false information.
If, for example, a member gets the information from a lunatic fringe website they spend a lot of time on, or they obtain information from cable TV ‘entertainment program’ masquerading as a ‘factual news source’, then no matter how removed from reality these sources have driven them, they could not reasonably be accused of lying for posting the misinformation they rely on to inform their view of the world.
In such a case, pointing out that the member is posting misinformation is not accusing them of lying.
It’s simply reminding them they are misinformed.