Bug - Message from a dead leader

[Leyrann]

I defeated Pedro II, taking his last city, getting his defeat message and seeing him disappear from the leaders in the upper right corner.

Then, some 5 turns later, I settle a city close to what his capital was... And I get a message that I'm settling too close to him. Okay..?

 

[Carazycool]

You settled on top of his ghost. Insult to injury.