I agree with Labarinth.
They are trying to pass off myth as fact. Sure if they want to believe those myths themselves fine, but don't try to tell other people they are facts.
It's exactly the same situation if I just made up some names and started walking around telling people these are our gods. It's not fact, it's not true, it's a lie.
Yes you are allowed to lie, first amendment right. But lie to the point that people actually start believing these stories as fact is too far.
A business is not allowed to go around spouting lies about anything. You can be accused of slander if you go around telling lies about someone else. Why should religion be allowed to pass off these myths as fact?
I hope the guy wins.