The green AI has a grievance that I stole "his wonder" but I took the Territory from Brown AI. No idea on how to recreate this, or, if it's a bug what caused the grievance. 

I did ask for him to surrender to an ally so maybe it just randomly pulled a grievance that it had against one of my territories? Or grabbed the highest priority grievance (wonder) even though that was a different AI / Player's action. It was odd though, thought I'd pass it along.

Norsemen Turn 105 odd grievance .ctr