Funny and amusing situations...

I came across this scam on an author-made map that I'm currently playing. The map is strategic, so getting +2 mana when the hero already has 333 mana is definitely not a fair trade! I'm playing as the Swamp faction, and I don't have any necromancers in my army at all, but I'd rather sell the Cloak to merchants or sacrifice it at the Altar for experience. I hope this is just an oversight by the author, because otherwise the map is quite good (if I finish it, I'll tell you about it; for now, I'm still far from success). Hmm. I opened the map in the editor. The author even took the time to add his own text to this seer. Is this some kind of mockery of the player? And besides: how did he know that I have a Vampire Cloak?