This probably isn't a bug, but more a case of me just not knowing how civ's with the BARBARIAN trait work because I haven't played one of them in a while...
I am playing as Jonas Endain and exploring the map. I did forget that the Animals can attack me at will, while I am asked if I want to declare war on the barbs or not whenever I have the opportunity to kill one.
But, this really got me...
It was not yet even turn 90 in an Epic game of 990 turns and I got very lucky and hit back to back techs (Construction and Sanitation) from goodie huts. Then, I got the message that the barbarians felt I was too civilized and were declaring war on me - I had more than 50% in score than the next civ (I'm pretty sure this is limited to only those civs I have had contact with - if so, it was only 3 AI civs so far on the Large map).
So, I still get the -10% hit on Research, but lose the peace with the barbs.
Fortunately, this happened before the load of raging barbs appeared so I could shore up my defenses, but it left me with 800+turns of my game left and reduced fun because I lost that BAR trait. My bad, sure, but I thought there was some sort of moratorium before this rule kicked in?
Oh one more thing, that I think is a bug. I had a Ruins in my borders (two tiles away from my capital city). When I was at peace with the barbs, no problem. However, when I finally killed the barb lizardman guard, I still couldn't destroy the ruins by moving one of my units on it. I'm thinking maybe I have to build an improvement on that tile to destroy it, but shouldn't be capable of destruction once I am no longer at peace with the barbs by simply moving one of my units on the tile?