So if you have facts and evidence that a CEO is good then just go ahead and post it in such a way that people aren't mislead or confused.
If you think something is a lie then explain the truth and present evidence to back up your case.
If you don't have evidence to prove that something's a lie or you don't have evidence to prove that someone is a good man then it's just your opinion that's just as valid as the person posting the opposing opinion.