Before that he had 0 fame so he most likely used one of the old fame exploits to gain that amount of fame long ago and then stopped using that account. RealmEye removes your characters from your characters page after 2 weeks of inactivity so he just was inactive for over 2 weeks and someday wanted to check out his account and bam it was there. RealmEye had removed that account so it seems that he earned all that in one day