User blog comment:FairyRaven/Fairy Tail Chapter 329: Seven Dragons, Review and Commentary/@comment-4643135-20130505013544/@comment-7418318-20130509071708

I wouldn't exactly call Zirconis a reliable source of information.

First off he's shown that he likes to troll Humans (and that Milky Way does not prevent him from lying). He might just have told them a scare story to amuse himself.

Or he might have told them what he thought was the truth and he might have been mistaken.

To make matters even worse, he was dead for 400 years and his soul was already in the process of vanishing from this world, so his memories might have been inaccurate, even if he had once known the truth and was willing to tell it to them.